- For the issue of the same name, see Diggle (issue).
- "She's a soldier... she understood. But I don't. And I don't think I ever will."
- —Diggle to Oliver on telling Lyla about killing Andy[src]
John Thomas "Dig" Diggle (born c. 1977) or "Johnny" to Lyla, is a former bodyguard, former soldier and a member of Team Arrow. John is the older brother of the late Andy Diggle, the husband of Lyla Michaels and the father of John "JJ" Diggle, Jr. (Sara Diggle in the pre-Flashpoint timeline). As a member of Oliver's team, John is his partner and plays a number of roles including field support, decoy and guidance to Oliver in times of doubt. John was known in the Suicide Squad under the code-name Freelancer. Later he took up a suit and was officially given the designation Spartan by Felicity.
John was born in 1977 in Starling City. During his childhood his father used to take him to see the games of the Starling City Rockets every week end with the subway, which was subsequently abandoned. The relationship between him and his younger brother Andy was always very tense. At one point, John discovered Andy was dealing drugs and punched him repeatedly until his knuckles bled. John attempted to make Andy take a proper path in life by enlisting in the military.
As an adult, John joined the United States Army and, in 2005, he held the rank of Sergeant; upon his honorable discharge from the Army, he held the rank of Master Sergeant. While with his unit in Afghanistan, the group ended up in a trap. The men of the unit were all killed, but John killed the entire group of assailants. When he discovered his brother Andy was a drug dealer, John beat him until his knuckles bled and convinced him to enroll in the army, hoping it would set him on the correct path.
John and Andy went on a mission in Afghanistan hoping to stop the local arms trade. On the way, their armored truck was attacked and their group was pinned down. John rushed out and planted a land mine while Andy and the rest drew the hostile truck towards it. The truck ran over the mine and exploded. Back at base camp, John and Andy were on guard duty. Lt. Joyner approached them and offered them a deal to confiscate some of the opium they recovered and sell it off. Andy appeared to reject the offer which pleased John, but John later caught Andy talking to Joyner. Andy played it off as a casual conversation about teaching Joyner to count cards, but lied to John and was actually helping Joyner steal opium.
After one of his times back home Diggle saw the "ghost" of a fellow soldier who had died, a symptom of survivor's guilt, and only made it go away once he figured out what the ghost was trying to tell him. During his time in Afghanistan, Diggle met Ted Gaynor, a fellow soldier who saved his life from the enemy.
First marriage with Lyla Michaels
Lyla Michaels and John met in Afghanistan, and then got married. At the end of John's second tour, they rotated back Stateside, where their marriage could not survive the peace, and they divorced. John went back to Afghanistan for a third tour, while Lyla joined A.R.G.U.S..
Becoming Oliver Queen's bodyguard
Diggle was hired by Moira Queen to protect Oliver. However the very first time Diggle drove Oliver somewhere, he vanished from the car much to Diggle's annoyance. Later, Diggle went with Oliver again to his 'coming home' party and guarded him. However, when Oliver tried to leave Diggle tried to stop him but was knocked out, unknown to him that Oliver was actually heading next door as the new hooded vigilante to stop Adam Hunt. Oliver continued to try and avoid him.
It was revealed that Diggle had a brother, Andy, who died working as a bodyguard and thus left behind his wife. He discovered Oliver was the Vigilante after being shot by Deadshot, and was taken to Oliver's hideout to recuperate. After the said discovery, Diggle quit his job as Oliver's bodyguard stating how he did not approve the way "Oliver spent his nights". Oliver later went to Diggle's sister-in-law's restaurant where Oliver tried to change his mind about his offer, and also revealed to him that Deadshot was Andy's killer which made John begin to rethink his role as a bodyguard. Later Diggle showed up to Oliver's house and accepted his offer, just in time to see Detective Lance arrest him.
Working with the vigilante
After Oliver was put under house arrest for being accused of being the vigilante, which was actually true, Diggle was told about a crime lord that was in trading arms. Diggle thought Oliver intended to head out himself but Oliver told Diggle himself to observe his closet men. Later Oliver had Diggle go out himself donned the Vigilante costume in order to save Oliver from incarceration.
Diggle saw Officer Stan Washington get shot while attempting to stop a robbery and tried to convince Oliver to branch out from The List to help others. Oliver at first refused but upon being tricked by Diggle to visit the hospital Stan Washington was staying at and seeing his wife, Oliver agreed to help catch the Royal Flush Gang. That night, they hacked the bank cameras and attempted to find footage to help identify the members of the gang. However, the camera footage isn't enough and Oliver decided to break into the police station to get the information needed. Upon identifying the members of the Royal Flush gang, Oliver and Diggle found out they were families that were hurt by the corruption of Robert Queen and Oliver attempted to give them a second chance by giving the father of the gang a job. Upon being refused, they decided to take down the Royal Flush Gang.
After Oliver failed in taking down the Dark Archer, Diggle drove Oliver to a hospital and told everyone he was hit by a semi while riding his motorbike. John tried to convince Oliver that his former commanding officer, Ted Gaynor, was a good man. Unfortunately, he was wrong, and it nearly cost him Carly's life.
Diggle was surprised to see Felicity Smoak come to the Arrowcave but discovered Oliver was shot. He saved Oliver's life with blood that Oliver stored away for a "Rainy Day" which Diggle referred to as it "Pouring" as Oliver was near death. He later used defibrillators to resuscitate Oliver when he went into cardiac arrest. Afterwards he was talking to Felicity, about him and Oliver, and she commented on how bad all their lies had been and Diggle told her that it was thanks to her, that they'd been able to do half of their work.
Concerned with the rising danger of their missions, John tried training Felicity, wanting her to be capable of defending herself. After Oliver's return from an earlier mission John asked how it played out, and Oliver answered "Bad for him". Oliver then informed John and Felicity that his target was Guillermo Barrera, an assassin, and he needed Felicity to hack his phone in order to figure out who Barrera's target was. When Felicity hacked Barrera's phone she was able to see that the last number that was called was to a restaurant called Jade Dragon, and John revealed that it is a front for the Chinese Mafia. Then when Felicity had hacked the phone they saw that the target is Malcolm Merlyn. He interrupts Oliver and McKenna Hall's date and informs Oliver of who the target is. After Oliver got back from saving Malcolm, Oliver informed John that Malcolm was taken to the hospital stating that it was good he wore a bulletproof vest. Oliver tells him that Malcolm is not at the hospital for being shot, he is there because of being poisoned by curare. John then realized that Floyd Lawton, his brother's killer, is still alive.
John was watching the Starling City Sentinels report of Deadshot's kill until Oliver arrived and John showed him a video of Helena Bertinelli killing Gus Sabatoni, and he warned Oliver of that she might tell someone about them and their operation. Oliver told John he wanted him to get in touch with their contacts in the Bratva and ask anyone in the street if they know why Helena is back and what she want. Later Oliver told him that Helena paid a visit to his house and made a treat and he want security on his mother and sister. John told him that he was way ahead of him. Later when Helena had blackmailed Oliver into helping her kill her father, John talked to him about Helena thinking Oliver should kill her, the Oliver asked him what he would do if it was Floyd Lawton and he answered not what Helena is doing. Oliver called him and when he came to Felicity's office there he found Oliver freeing a tied up Felicity.
Oliver tried to take down John Nickel, a corrupt businessman but when Oliver arrived he was already taken by someone else. After Oliver attempted to go after someone else on the list Dig took the list from him and insisted that he give it a rest and the two went to Big Belly Burger. Dig expressed his concern about how Oliver is handling the drama in his life whilst being the Hood such as his flings with McKenna and Helena but everyone in the bar got a video streamed onto the phones of a man named "Savior", real name Joseph Falk, had Nickel strung up and killed him. Later Joseph did the same again to Gavin Carnaham as Oliver tried to find him with Felicity's assistance but was too late. Later while trying to find a way to narrow Joseph down Dig noted the train moving sounds in his broadcasts and realized that they were in a subway car which lead to Oliver saving Roy Harper from him.
John and Oliver planned to take down Deadshot. With Felicity hacking A.R.G.U.S.'s database, they learned that Floyd was returning to Starling City to meet a potential client, which really was A.R.G.U.S setting a trap for Deadshot. When John went to the mall, the trap was already taking place. He observed the A.R.G.U.S agents (including Lyla) while waiting for Floyd to show up and when Floyd was started sniping the agents John quickly ran towards Lyla, and was able to save her and then he ran to stop Floyd from escaping. John ran into Floyd in the staircase, the two fought, and Floyd got hold of John's gun. Floyd held John's gun at his face, and he forced him to fall on his knees with his hands behind his head. John told Floyd "I'm gonna kill you for what you did to Andy". Floyd answered, "I would pull the trigger right now, but no one is paying me" and he told John, "I got space for you right here next to your brother", showing John his victim tattoo of Andy. Floyd then punched him in the face with his gun, and left John on the floor. Felicity later tended to his wound and when Oliver came back, John was angry at him for not showing up when he needed him. When Oliver later tried to get on the same page as John, John told him they were done with each other and quit being a member of the team.
Felicity went to John and told him about the new lead. He said he would come back as soon as Oliver apologized, but because of his stubbornness to admitting he had been wrong, he knew Oliver wouldn't. After overhearing Moira and Malcolm talking, Oliver realized that he would need all the help that he could get. Oliver apologized to John, and told him about Moira's involvement in The Undertaking, saying he needed John's help to stop it.
John was back on the team. He pretended to be the Vigilante to get information from Moira, hitting Oliver to gain information. He was meant to draw back his punches, but Oliver came back limping and injured. Later Dig assisted in getting Oliver and Felicity into Merlyn Global to find out Malcolm's plan with Dig posing as a security guard and even helping Felicity out of trouble when she was almost compromised. Later Oliver confessed that once Malcolm was dead that he would stop being the Hood to a surprised John and Felicity. Later when Felicity found the device Oliver sent John to disarm it while he handled Merlyn. However the device was gone and Oliver was overpowered and captured by Malcolm.
Diggle saved Oliver from custody of Malcolm Merlyn and the two returned to the Arrowcave with Felicity. Later Oliver, Diggle and Felicity analyzed the date for Merlyn's timetable and discovered the device to be in the railway tunnel under the city and Diggle was present as Moria confessed the truth on the news. Oliver initially tasked Diggle to go after the device but he convinced Oliver to let him go with against Malcolm together while Detective Lance handles the device with Felicity's tech support. They briefly engaged the Dark Archer, but John got injured and has to let Oliver go without him. He managed to get up the stairs in time to see Oliver kill Malcolm. Before dying however Malcolm revealed that he had a second device which forces Oliver to left John as he realized that the earthquake was hitting Laurel's workplace.
Assisting the Arrow
John and Felicity traveled by plane to Lian Yu, to convince Oliver to return home. Oliver initially refused, but he and Felicity convince him not to return as the vigilante, but as Oliver Queen, because he's needed more than ever as his mother's trial was coming up and a takeover of Queen Consolidated was imminent. Later, Oliver found out that John lied to him, and only wanted him back to catch the group calling themselves, The Hoods. In a board meeting, The Hoods came after Oliver Queen, trying to kill him, but John intervened. John and Felicity were later left wondering why Oliver avoided attacking The Hoods. Oliver told them that they aren't considering the body count, Felicity asked him why he cares now, and John realized it was "since Tommy". Later Oliver, Felicity, and John went to the upgraded HQ to plan to take down The Hoods, who have now captured Thea.
John and Oliver visited the Glades Memorial Hospital, and he told Oliver how people from the earthquake ended up there. John and Oliver saw Sebastian Blood talking to press outside as they left the hospital. John told Oliver that Sebastian had very strong opinions and that he believed the Glades had been abandoned, and that no one gave a damn about the people in the Glades. After a quick chat between Oliver and Sebastian, they left, with some of the protesters becoming violent. Later, John and Oliver, as The Hood, take on China White and Bronze Tiger. John drove away in one of the trucks, but is soon after attacked by China White, and they faced off. As China White gained the upper hand, Oliver shot a trick arrow at her, pinning her to a nearby pole.
Lyla Michaels was missing in Russia, having been captured during an Intel operation in a Russian gulag. John was recruited to break her out, because A.R.G.U.S. did not have sufficient resources for the operation, and her superiors already consider her disavowed and dead. Oliver and Anatoly arranged to get John arrested and sent to the prison, where he found Deadshot, whom he teamed up with to break Lyla out of jail. Afterwards, John chose to spare Deadshot's life rather than kill him in cold blood. In return, he was informed that an organization called H.I.V.E. hired Deadshot to kill his brother Andy. After returning to the States, John and Lyla rekindled their relationship.
John collapsed after being unknowingly dosed with Vertigo. He was taken to the Arrowcave to recover. While recuperating, he and Felicity deduced that Count Vertigo was distributing the drug to the citizenry of Starling City through flu vaccination trucks.
While Felicity was growing jealous of Sara Lance, Diggle comforted her with little success. Later he went out with the rest of Team Arrow to stop William Tockman. After being told that the pressure valves would destroy three city blocks, he managed to cool them down just in time.
Diggle and the rest of Team Arrow went to take down Slade Wilson at the Queen Mansion. After Oliver got him outside, he was knocked unconscious by an unknown accomplice before he could take the shot. Slade later assures Oliver that he is alive for now.
John and Lyla are recruited by Amanda Waller to lead the Suicide Squad on a mission to destroy a nerve gas in the possession of Gholem Qadir. John argued with Lyla about Waller's methods when the A.R.G.U.S. director killed Shrapnel for attempting to flee the mission. He was disgusted by Waller's callous disregard for the lives of her agents, while Lyla supported her boss. He managed to get an invitation to a party at Qadeer's mansion, which Deadshot used to infiltrate the premises and locate the nerve gas. When A.R.G.U.S. sent a drone to destroy the mansion, John persuaded Deadshot not to sacrifice himself for the mission. He persuaded the guests to leave by denouncing Qadeer in front of them, and he, Lyla, and the squad flee. He later reconciled with Lyla, saying that she was more important to him than sticking rigidly to his principles. In a flashback sequence, John was seen serving as a soldier in Afghanistan. He helped capture Gholem Qadeer and saved his life when their group was attacked. He was also seen meeting Lyla for the first time.
John along with Sara, Oliver and Felicity broke into Queen Consolidated's Applied Sciences Division. Working to get everyone in outside before they set off the bombs. When Oliver went to kill Slade Wilson Diggle backed him up by shooting Isabel before she can kill Oliver.
Diggle and Felicity attended Moira Queens funeral. Afterwards they continued to search for Oliver. They were forced to go to Amanda Waller for help. Later he along with Oliver, Felicity and Laurel went to cripple Slade Wilson's army. He was about to set of the charges before Isabel Rochev stopped him and threatened to kill him.
Return of the Church of Blood
After The Arrow and Roy grappled on to a drug plane, Felicity attempted to hack the plane's Wi-Fi, though when she couldn't get a clean signal, Diggle suggested "plan B", namely invading the plane and placing an auto-pilot device in the cockpit. However, while they were doing so, Roy was shot by one of the men they had not knocked out. As he fell from the plane, Oliver suggested Dig prep for surgery. When they returned to the foundry they performed the surgery. Deciding that all they could do was wait, Dig left to tend to a pregnant Lyla.
Sometime later, Dig went to visit Lodai, their supplier. He commented on Lodai's paranoid guards, and promised to bring more money for the goods "next time", a claim that Lodai had heard numerous times. He called Oliver to update them, mentioning how their transactions were much easier when Oliver was a billionaire.
Following her run-in with a member of the Church of Blood, Laurel returned to the base to tell the team of her news regarding a resurfaced Brother Blood. Despite the original Brother Blood, Sebastian Blood, being dead, Diggle suggested Oliver go check out St. Walker's Church, an abandoned orphanage that Sebastian had been raised in. After Oliver didn't check in, Dig went to provide backup. He attempted to enter the church, but was distracted by a follower, only for another to come up behind and knock him out, identifying Diggle as one of the two people Brother Blood had been looking for. Diggle was then taken to Brother Blood himself. Blood revealed his identity as Clinton Hogue. He began questioning John as to why he was inquiring in to Sebastian Blood, but was interrupted by The Arrow. Dig was untied and they ran off, running in to some more followers. Oliver threw down a flechette that caused an eruption of smoke, allowing them to climb to their safety. Once they reached the surface, some Vertigo that had entered Oliver's system began acting, causing him to believe Diggle was various ghosts of people gone by. The two began fighting and Oliver gave Diggle a number of bruises and bad injuries. However, he was able to hobble away to Verdant, where he was found by Sara Lance. He was taken inside before she left to find Oliver. He explained what had happened while they placed Oliver on to a bed. Once Oliver woke up, he apologized for giving Diggle the injuries, before running a blood test and finding traces of mushrooms in Oliver's system.
Diggle returned home, where Lyla told him of her mission to Kahndaq. He refused to let her go, instead suggesting that he should go. She was happy with the deal, but let him know that he'd be going with the Suicide Squad. He called Oliver to check in and let him know he'd be going before meeting up with the rest of the Squad. They headed out to Kahndaq, during which time Diggle met Ravan Nassar. When they arrived, they all parachuted to the ground. They headed in to a city, where they disguised themselves (except for Deadshot, who scoped from afar). Before someone could be executed, Deadshot shot him and the rest began eliminating Onslaught members. As they began to escape, a truck blew up due to an IED from Ravan. Dig was annoyed as they had no way to Onslaught leader Khem-Adam, but they managed to find a survivor to interrogate. Inside a building in the city, Diggle ate some food provided by an old man, while the others interrogated the captured man downstairs. He headed downstairs and stopped them from torturing him, instead talking it out. The man revealed Khem-Adam's location in the Ahk-Ton Desert. They headed out on camels, before they blew through a side of the Amon-Shu Caves. They began eliminating Onslaught members, while Ravan and Diggle helped to rescue the kidnapped girls. Khem-Adam was taken by The Canary and Nyssa al Ghul, and the Suicide Squad headed back to America, burying Ben Turner in the Ben Turner in the Iron Heights cemetery.
Caleb Green's vengeance on Oliver Queen
Dig soon returned home, meeting Felicity and Roy in the base. He claimed to feel like sleeping for a whole week on Oliver's bed, but they were interrupted by the news, on which Oliver, masked, was fighting a man in the streets. Before they could be caught by the police, Diggle suggested that Roy use a grappling arrow to climb up the building. They did so, but were soon caught by police. However, Felicity was able to intervene, impersonating a police chief. They returned to the foundry, where Diggle joked about Oliver wanting a new look with the hockey mask, refusing the cover himself. They soon discovered the identity of the man, Caleb Green, and his motives. After Oliver decided that the only course of action was to return to Lian Yu, John was in disbelief.
Becoming a father
Diggle assisted The Arrow and Roy in the field as they captured Vincent Stilgrave. Later he got into a heated argument with Oliver, who forbid Diggle from putting his life in danger as he's about to become a father. When Oliver visited Diggle and Lyla in the hospital, Diggle admitted that Oliver was right that he should be with his daughter.
Despite being told to be with his family, Diggle told Oliver he will help go after the man who killed Sara. Diggle had the belief it was a member of the League of Assassins who killed Sara but was told they'd never go after their own kind. Given access by Lyla, Diggle used A.R.G.U.S. in search of possible suspects for Sara's murder, to which he found Simon Lacroix, a mercenary archer who wears a full face mask. At Sara's burial, Diggle informed Laurel that he and Lyla decided too name their baby Sara, to which Laurel was thankful to hear. After hearing Simon Lacroix wasn't Sara's murderer, Diggle told Oliver he'll stay until the killer is caught.
Lyla asked Diggle to follow Oliver to Corto Maltese and check up on an agent, Mark Shaw. Diggle made contact with Shaw and verified his identity with a security key that contained the identities of all A.R.G.U.S. operatives and their families, only for Shaw to double-cross him and steal the key in order to sell it. Diggle and Oliver inform Lyla and she told them to wait while she sends an A.R.G.U.S. tactical team to handle the situation. However, they ignored her and attacked Shaw as he met with his buyers. Enraged, Diggle chased down Shaw, beat him, and demanded to know what gave Shaw the right to endanger his family by selling the key. Shaw replied that it was his only escape from A.R.G.U.S. and Amanda Waller, who he felt had taken over his life. Later, when Diggle returned to his family, Lyla said she had to go to A.R.G.U.S. to report to Waller, and Diggle looked briefly troubled.
After Nyssa returned and announced Malcolm is still alive, Diggle asked what her source was. Later Diggle along with Nyssa and the team went to Ken Zhi Jansen's temple though Diggle only found his grave. After Oliver tagged Malcolm with a tracker, he was told to track Malcolm and was told that even an idiot could run it. Later, Oliver had Diggle secure the perimeter as Oliver couldn't risk Thea seeing him.
When Brother Eye shut down the power in Starling City, John arrived by Verdant to go down the arrowcave though he had to bring his child as Lyla was out on a mission and the nanny called in sick. Oliver told Diggle he wasn't comfortable with a baby down in the cave. John left his child in the care of Donna Smoak. When Oliver was worried Felicity was taking too long, Diggle told Oliver that an A.R.G.U.S. agent dropped by not too long ago to pick up his child and that he'd tell him to go back and check on them. Diggle later arrived to stop Brother Eye from robbing the truck of cash.
Diggle, Oliver, and Roy looked for a drug dealer under the alias of "Pakko", where they found the word "Guilty" written with blood. Diggle later believed that Ted Grant was the culprit despite Laurel vouching for him. After Roy revealed his nightmares which he believed was true, Diggle stopped him when he tried to leave though Oliver told Diggle to let him go. Diggle later told Oliver that he should cut Roy loose as he believes he isn't fit to be on the team, believing he really did murder Sara. Diggle and Oliver later went to rescue Laurel and Ted, who were kidnapped by Isaac Stanzler. Diggle later pulled Ted out of the car, who went unconscious briefly went Laurel lost control of the car.
He later helped Oliver as Felicity was gone and a mysterious archer had killed Isaac Stanzler with an arrow with a spade-shaped point. Oliver was frustrated with Felicity hooking up with Palmer. John talked with him about it. Oliver discovered a small letter in the arrow that had killed Isaac Stanzler. The address of an apartment was in it. The two of them broke into the apartment and searched it. Surprised, they noticed there were articles of newspapers on the walls about the arrow. There was even a shrine where arrows of Oliver's were displayed. Without their knowledge, a red-haired woman was watching them from a nearby building. Oliver realized the spade arrow was actually a heart. Carrie called them with a cell phone that was laying on the table. She told Oliver she wanted to be with him and then send him a picture of a mob boss with a bomb vest she wanted to kill. Felicity identified the unknown woman as Carrie Cutter a former SWAT officer. John stayed at Verdant as Roy and Oliver went to Sherwood to confront Carrie and free the mob boss. John found out Carrie had been obsessed with a former Colleague and had received therapy from a psychiatrist. John tried to comfort Oliver and invited them to diner with him and Lyla. John later found out Carrie had killed a hacker and learned that he had made an algorithm for her that traced the Arrow his activities back to Verdant. He quickly informed Oliver after which he looked for Thea to protect her. Oliver went back and called her and managed to agree a meeting with her and made her leave the club. John and Felicity were following Oliver through his earpiece as he went to the place he first saved her. They heard the conversation through Oliver his earpiece as he tried to convince Carrie he could not be with anyone. Carrie called him a liar and attacked him. She made both of them fall down into a train tunnel which disrupted the signal of Oliver his earpiece. Diggle and Felicity were no longer able to follow Oliver his signal as he was down below. Oliver got defeated by Carrie who cuffed him. Carrie wanted both of them to get run over by a train in an attempt to be together in death. Oliver managed to dislocate his thumb and pulled both of them away from the speeding train. John was relieved learning Oliver had survived and he later told him Carrie had joined the Suicide Squad. John told him he knew Carrie could notice it when people lie and said that perhaps Oliver was lying to himself when saying he could not be with someone. John invited Oliver for a late dinner and was joined by Oliver and Roy just as they begun.
Diggle later joins Team Arrow, excluding Roy, to Central City to determine who committed a homicide involving a boomerang, given that the boomerang is made of iron oxide, which is highly abundant in Central City. When Oliver returned to their hideout, Diggle was startled by the sudden appearance of Barry, who had gained superspeed and was calling himself the Flash. The only things Diggle could say was how fast Barry had become and that he had a cousin who developed a stutter after being struck by lightning. Barry suggested they team up to find their boomerang murderer and to catch Roy Bivolo, a meta-human who could induce rage in people. As Barry carried Felicity all the way to STAR Labs to analyze the boomerang, a perplexed Diggle asks Oliver how he isn't freaked out by Barry's abilities. He still brings it up while waiting in the truck as Oliver searches the warehouse where Bivolo was last holed up, though Oliver assures him that Barry is still the same person they met a year ago. Later, after Barry becomes affected by Bivolo's powers and Dr. Harrison Wells subsequently deduces Oliver's identity as the Arrow, Diggle joins the others at STAR Labs. Cisco boasts that he suspected Oliver as one of the many he theorized to be the Arrow. After Wells and Joe West snap Barry out of his rage, he and Oliver captured Bivolo and imprison him in STAR Labs' Pipeline. Afterwards, Team Arrow parts ways with Team Flash.
A week later, Diggle keeps watch on a neighborhood where their boomerang suspect is held up while Oliver and Roy storm his hideout. Sadly, their man had already left and the pair are confronted by an ARGUS squad, revealing that the murder victim was an ARGUS agent. Though ARGUS told them to let this go, Oliver refused to. Diggle was sent to Lyla to find out who the culprit is, expecting that she would remain tight-lipped. Though Lyla insisted that ARGUS had it handled, the boomerang killer attacks ARGUS, forcing Diggle to call Oliver. They managed to drive the attacker away with the sudden appearance of the Flash. Under pressure from Oliver, Lyla identifies the man as Digger Harkness, an ex-ASIS agent who was recruited into the Suicide Squad, only to go rogue after a mission in Tanzania went south and Lyla ordered the Squad's termination, only for Harkness' bomb to malfunction. Returning to the Arrowcave to safeguard Lyla, with pieces of Harkness' boomerangs, Teams Arrow and Flash agree to another team-up. Barry then quickly reassembles the boomerangs and Cisco identifies their manufacturer, Klaus Markos. Barry later consulted with Quentin on Markos' last known whereabouts. As the team prepared to infiltrate Markos' hideout, Diggle was assigned to guard the perimeter due to his concern for Lyla. The only thing the raid produced was a cellphone, which Felicity used to track Harkness. But upon arriving at his hideout, they only find his cellphone, revealing Harkness had played them. They returned to the Arrowcave, only to find that Harkness had found the place by tracking the cellphone, his attack leaving Lyla critically wounded. Barry quickly rushed her to the hospital. While the rest of the team tracked down Harkness, Diggle remained by her side until she regained consciousness. He then proposed to her.
Diggle donned Oliver's costume after the latter disappears fighting Ra's al-Ghul and masqueraded as the Arrow in order to make it appear that the vigilante was still protecting Starling. He advised Felicity to prepare for the possibility that Oliver was dead. He then went on a mission to prevent Brick from seizing police evidence that was being used to keep many of Starling's criminals in jail, during which he ended up facing off with Brick himself. Despite shooting Brickwell directly in the head, he was savagely beaten before Arsenal intervenes. Afterwards, he discovered that Felicity let Brickwell escape with the evidence in order to save him and Roy, and angrily protested that she had no right to make that decision without their consent. When Malcolm Merlyn gave Team Arrow proof that Oliver indeed died at Ra's' hands, Diggle insisted on continuing Oliver's work without him; Felicity disagreed and said that there was no point in continuing. Diggle later spoke with Laurel, reflecting on his relationship with Oliver and admitting that he still thought of himself as Oliver's bodyguard, saying that he had failed to protect him.
War against H.I.V.E.
Months after Ra's al Ghul's attack on Star City Diggle took up a suit and became the leader of Team Arrow while the team were fighting thugs known as "Ghosts". After the city leadership was killed by the Ghosts Laurel and Thea brought Oliver back to Star City to help. Diggle was not pleased with the situation but accepted his help. When the team was able to locate the leader of the ghosts the team ambushed them but Darhk escaped. The Ghosts next target was the Star City train station so the team monitored the station before Diggle confronted Oliver and told him that he could not forgive him because Oliver was incapable trusting anyone. After Damien Darhk nearly killed Oliver, Diggle was able to save Oliver before his death and stopped the bomb threat.
When the Star City Dam was under attack from H.I.V.E, the team saved the dam from them and stopped the bomb before it could explode. The team started looking into Lonnie Machin, who was hired by Damien Darhk to kill mayoral candidate Jessica Danforth. While Laurel and Diggle were staking out the police station, Diggle revealed that he believes that the ghosts were responsible for his brother's death. When the team were able to locate Machin, Diggle and Laurel took an injured Madison Danforth to safety.
Oliver and Diggle were forced to work together as Thea and Laurel were away. The two track two members of H.I.V.E. but both got away before they could be interrogated. Later when Diggle returned home he found an A.R.G.U.S. agent who gave him photo of the person who hired Floyd Lawton to kill his brother, Mina Fayad. Diggle tracked her to a meeting but got away while he was under fire. When Oliver was attacked by meta-human Jeremy Tell Diggle and Oliver finally talked and told Oliver about Fayad and asked for his help. However, when they were able to track Fayad she had been killed by Damien Darhk. The pair took on Tell and after Oliver saved Diggle's life from some of Tell's tattoo playing card projectiles, John was able to defeat him. Oliver earned back Diggle's trust for being willing to take a "bullet" (tattoo projectile) for him. He, Oliver, and Felicity celebrated with drinks afterwards. 
Oliver told the team that he planned to run for Mayor which Diggle thought was a joke until he realized he was being serious. Diggle then joined the rest of the team in seeing the new Arrowcave. When a team of rogue police officers killed two police officers and started stealing drugs from dealers, Diggle joined Thea in buying some to lure them out. The team were later able to arrest to police officers with the help of Captain Lance.
Oliver had Diggle and Quentin work together when Damien blackmailed Quentin into installing a data eraser into a federal server farm. They entered the server farm and saw the device begin erasing files on various people including Andy Diggle. Soon an alarm tripped and two guards spotted them. Quentin hit John and faked arresting him as part of an SCPD sting. The team later regrouped at the Arrowcave when Sara Lance attacked Thea again and devised a plan using Thea as bait to lure Sara out. Thea waited in Verdant until Sara bursted through a window. Diggle rushed Thea to safety while Oliver and Laurel captured Sara. Later, Diggle was present when Oliver's old friend John Constantine performed a ritual of restoring Sara's soul to her body. Quentin later paid him a visit and gave him a file from Darhk about his brother.
After Team Arrow discovered Ray was alive, Diggle accompanied the team in stealing a quantum manifold from Kord Industries. Later at the lair, Diggle tried to calm Felicity when she was angered by their insistence that they wait until Quentin could give intel on Darhk's hideout. After Oliver glumly returned from dinner with Felicity and Donna, Diggle fetched some whiskey (a replacement for the vodka from the old lair) he stashed and listened to Oliver vent about his relationship problems. Diggle realized Oliver was feeling jealous of Ray but assured Oliver that Felicity chose him, not Ray. The team later regrouped and formed their plan to rescue Ray. After knocking out a Ghost, Diggle took the uniform and masqueraded as one to infiltrate the base and the team was able to recover Ray.
Diggle accompanied the team in fighting off a Ghost attack on a Star City Bank armored truck. However, the Ghosts were successful in destroying the money. After debriefing in the lair, John asked Oliver to stay behind so that he could show him the file that Lance gave him on Andy. Diggle later joined the team when they were breaking into Wolfman Biologics. After knocking out a Ghost, Diggle pulled his mask off revealing the Ghost to be his dead brother Andy. Andy then escaped. John was distraught that his brother was a killer and working for H.I.V.E. At the police gala, Diggle and Laurel talked over their shared experience with resurrected siblings. Diggle and Oliver then go after a H.I.V.E. gathering at the Docks, watching as Damien give new H.I.V.E. inductees mind-altering yellow pills. They are spotted so they fought off the Ghosts. After the debacle, Diggle told Oliver to drop it as he had lost hope in Andy. Oliver hadn't lost hope and refused to give up on Andy. Diggle also told him off for Oliver's plan to use his mayoral campaign to get in bed with Damien. Ray tracked H.I.V.E. to the Muller Psychiatric Center so the team attacked the base, looking for Andy. The team, with timely help from Ray Palmer, recovered Andy from H.I.V.E. Oliver also told John that he would take his advice and not use his campaign to get into H.I.V.E. He then went to Andy (who was being kept in a cage in the Arrowcave) and asked him if the bad things he did in Quentin's file were true, which Andy confirmed.
At Oliver's bay cleanup, Diggle was down because his brother was finally home, but in a cage. He had another talk with his brother, trying to find out why he would abandon his wife and child and pleaded for him to renounce his ways. Diggle later supported Oliver's plan to expose Damien Darhk to the public. Diggle used his contacts to recruit marines for security detail at Oliver's campaign holiday party. However, Damien Darhk showed up, took out the security, and kidnapped Diggle, Thea, and Felicity. The three of them were put into a gas chamber. After Oliver turned himself in to free them (but Damien went back on his word), Laurel and Malcolm (dressed as Green Arrow) arrived and were able to rescue them from the chamber.
After Felicity was shot by H.I.V.E., Oliver was unable to get a lead from any ghost so he had John beat up Andy to try to get him to give up information on Darhk. He went to see Felicity before her surgery. He then went home and had a talk with Lyla about Andy. Lyla told him that he was too busy seeing him as a traitor and that he needed to reach out to Andy as a brother. Team Arrow was able to find a lead on Lonnie Machin, who was already after Damien Darhk, at his foster parent's house so John accompanied Team Arrow to the house. After getting tangled up in one of Machin's traps, they disabled the auto-guns and captured Machin. Later, he revisited Andy who told him about how he was able to fool John in believing he was doing good during their time in Afghanistan. Andy also told him about Darhk's vision of a world reset and that he believed Darhk's message due to what he witnessed in Afghanistan. John pleaded to him that Darhk had hurt a friend of his and crossed a line. Andy thought about it and then gave John a lead, Stonehaven. John later checked in on Oliver and discovered that Oliver broke Machin out of police custody. John reminded him not to lose his humanity in going after Darhk. John forced Oliver to go see Felicity. Team Arrow discovered Machin's next target was Stonehaven, which was Darhk's place of residence. Oliver and Thea distracted Machin while Laurel and John untied and ushered Darhk's wife and daughter to safety.
While John and Lyla were on a date, A.R.G.U.S. agent Alan Chang showed up asking for their help. A group of armed men then kidnapped him. John jumped onto the van to try and save Alan, while Lyla opened fire but the van got away. After briefing Team Arrow and delivering food to Andy in the basement, John and Lyla went to A.R.G.U.S. to talk to Amanda Waller. Waller handed them a flash drive containing information on Shadowspire, a war profiteering group. Knowing that Andy used to be in Shadowspire, John had another talk with Andy about Shadowspire. Andy told him he wasn't a part of the organization anymore but that he could help Team Arrow capture them and told John that Shadowspire tends to use the nearest free port for its operations. Team Arrow discovered they had kidnapped two other A.R.G.U.S. agents and tracked Shadowspire to Pacific Freeport, but the agents were found dead. John then brought Andy to Amanda Waller where Andy could brief Waller on how Shadowspire worked. Later, Shadowspire attacked A.R.G.U.S. and held the command center hostage. Lyla was able to get a video feed down to the detention center where John was monitoring Andy. John used the TV monitors to broadcast a signal to the Arrowcave. John then planned for Andy to fake betraying him and tell Joyner that he was in the ventilation shafts. He was caught by Joyner's men and Andy double-crossed Joyner so a fight broke out. With the arrival of Team Arrow, they were able to stop Joyner from access A.R.G.U.S.'s Rubicon codes. John then took Andy to his home for dinner and had him meet his niece as gratitude for saving his life.
When Team Arrow caught Roy after stealing a network mapper from AmerTek, a triode capacitor from Cadmus Tech, and Palmer Tech's new power cell from Curtis, Roy revealed to the team that someone named The Calculator found him in Hub City and blackmailed him to steal the web-nuke components. Team Arrow tracked Calculator's target to the Flint Hill Data Farm and with Roy's help, they were able to stop the web nuke.
Nyssa and Malcolm went to war with each other over the Demon's Head ring and the Lotus elixir; their civil war started spilling into the streets of Star City. While initially supportive of Oliver's diplomatic efforts, John told him that the only way that the violence could end and Thea saved would be for Oliver to kill Malcolm. John then joined Team Arrow in witnessing a trial by combat between Malcolm and Nyssa. However, Oliver took her place and fought Malcolm, defeating him. John congratulated him on resolving the war without killing.
Team Arrow followed Ruvé Adams following a mayoral debate rehearsal with John transporting Thea on motorcycle in the back of a truck. However, the team got caught in an ambush by H.I.V.E. ghosts allowing Ruvé to get away. The team later traced another possible H.I.V.E. base. John was briefly knocked out during a fight with the Demolition Team, and was ran out to safety by Oliver and Laurel. Diggle later got some intel from Andy pinpointing a warehouse that the Demolition Team were operating out of. At the debate, she got a call from Curtis who had decrypted the laptop and discovered the Demolition Team's next target was the debate hall. John attempted disarming one of the bombs but was blown back by a booby trap. The team was able to fight off the Demolition Team and disarm the bombs, allowing the debate to proceed. Afterwards, John attended Felicity and Oliver's engagement party.
Oliver revealed to John and the team that Damien had kidnapped William, Oliver's secret son. While looking for William, John supported Oliver's decision to keep William a secret since he was a father himself and understood the choices one makes for their child. John provided sniper cover when the team attacked a hotel that Darhk was keeping William, but they were unable to rescue William. With Mari McCabe's help, they located Darhk's compound where he was keeping William and the Khushu Idol for his magic. The team broke in, destroyed the idol, and rescued William leaving Damien to be arrested by the police.
John and the team returned from patrol noting how quiet the city's crime was with Damien Darhk in jail. John later testified against Damien but Darhk's attorney was able to use John and Thea's purchase of cocaine (from their mission to stop Liza Warner's crew) to destroy John's credibility. The team then got a hit on Carrie Cutter, who was back in town after her stint on Task Force X, and had killed one celebrity couple and kidnapped a second but Carrie got away. Oliver then arranged a fake wedding with Felicity to draw Carrie out. At the ceremony, Felicity and Oliver distracted her long enough for John and Thea to arrive and defeat Carrie.
After the defeat of Damien Darhk and the death of Andy at his own hand, John felt he needed some time away from the team and Star City, and decided to reenlist in the Army.
Effects from Flashpoint
When Barry Allen went back in time to fix the Flashpoint timeline back to normal, there were ripples in the current timeline. One effecting Diggle was that he never had his daughter Sara and instead he now has a son named John Diggle, Jr., nicknamed "JJ".
Reenlisting in the Army
Once Diggle left the team he reenlisted in the army to find some clarity. He went to Chechnya to serve time there. He was commanded to take his men on a mission and obtain a piece of a bomb from Genesis Day, before Chechen rebels could. On the mission Diggle and his men were caught in a shoot out killing everyone but Diggle and another soldier. The two found out it was all a setup so the U.S. Army could obtain the weapon and Diggle was blamed for trying to steal it.
John was then sent back to the U.S. to be held in a military prison were he began to lose his mind. While in prison he started seeing hallucinations of Floyd Lawton, the man Dig thought killed Andy. When Lyla visited him she told John she would try to get him out, but John told her not to. Lyla then told Oliver the news and the two of them came up with a plan to break Diggle out. Oliver broke into the prison to free Diggle with Lyla assisting him. Once Oliver got Diggle out of his cell they attempted to escape the prison. Once they got outside a group of soldiers stoped them in their tracks not before Oliver and Diggle strapped on harnesses and were pulled into the air by a plane flown by Lyla.
Returning to Star City
Once free from the military prison Diggle returned to Star City. John had to live in the old H.I.V.E. headquarters due to him being on the run. He later rejoined Team Arrow and took back his old role as Spartan this time with an upgraded helmet. Diggle also became a mentor to new member Rene Ramirez, giving him the respect and advice that Oliver didn't. In November 2016, JJ turned two years old and had a birthday party, but Diggle was unable to attend due to him being a fugitive. Instead, they held another party for him, at the H.I.V.E. bunker in which he was staying.
A few days later, Oliver and Diggle were tracking down another vigilante showed up who goes by the name Vigilante and engaged him in a shoot out. As Vigilante was about to shoot them The Flash came to their rescue and ran them to Felicity's apartment. Barry told Oliver he needed their help along with the Legends and Supergirl to fight the aliens known as the Dominators, who invaded Earth to exterminate all meta humans. When the Dominators mind controlled the heroes with the exception of Oliver and Barry, Diggle fought them until they managed to broke the device mind controlling him and the others. Later Oliver, Thea, Diggle, Ray, and Sara were sucked up to the Dominators mother ship and placed in a shared hallucination were John operated as the "Green Arrow" after returning home from the war and leaving the Army as his penance for all the things he had to do over there. He worked alongside Felicity Smoak. Diggle along with the others slowly realized that this was fake and they all escaped the hallucination. Once they escaped the team later defeated the Dominators and saved Earth.
War against Prometheus
Upon figuring out that Prometheus had connections to Justin Claybourne, one of the Hood's victims, John accompanied Team Arrow in investigating Claybourne Pharmaceuticals. Prometheus had been waiting for Team Arrow and let them through, where Team Arrow discovered Evelyn had been working with Prometheus and betrayed the team. Later that same night, John gets a call from Lyla telling him of trouble. John rushes into his home with his gun drawn, only to find it filled with armed snipers and he gets taken into custody.
John is back in prison and to be charged with his treason against J.G. Walker, where in reality he was framed for a crime committed by the corrupt general. Oliver as mayor enlists Adrian Chase who reluctantly agrees to serve as John's lawyer and help exonerate him. After several attempts to delay John's transfer to prison, Adrian tells John to punch him. Under the pretense that John attacked Adrian, Adrian declares that committing such an offense against the district attorney was within his jurisdiction, which delays John's transfer for a week. Shortly after Felicity's dealings with Helix allowed her to acquire what she needed to place criminal charges on Walker, which was sent to the NSA before Adrian received it and sent it to a judge who allowed John to walk free.
In a reality created by Eobard Thawne using the Spear of Destiny, Spartan was killed by Damien Darhk along with Green Arrow, Black Canary, The Flash, Ragman, Wild Dog, Vigilante and later Felicity. All of their masks were kept as trophies in Darhk's office.
Grant Wilson's uprising
In a potential future, by the year 2031, during Grant Wilson's takeover of Star City, he was killed, causing his son to change his name to Connor Hawke, believing he didn't deserve his father's name.
Contrary to his seemingly tough exterior, John is a very perceptive and wise individual, being the first to notice that something was different about Oliver Queen after he came back from the Lian Yu. This was what prompted Oliver to have him as his comrade. John hated personal security because he was simply serving wealthy spoiled brats instead of making a difference in the military. This was what inspired him want to join Oliver Queen's crusade after Oliver saved him from poisoning by curare, learning from Oliver his brother was killed by the assassin Floyd Lawton and a conversation with his sister-in-law Carly Diggle made him realize Oliver was making a difference and was offering him a chance to do the same.
Since becoming Oliver's first partner in his crusade, John has provided Oliver with a greater sense of direction, such as when he suggests tracking down other dangerous individuals and providing protection for the innocents instead of simply hunting down the men in his father's book. John sometimes serves as the voice of reason for Oliver who, sometimes being impulsive isn't thinking his actions thoroughly, keeping him grounded and realistic. John was also very wise because even though he was against Oliver killing as a first resort at the beginning of his crusade, he still allowed Oliver to do so, hoping he would learn to show restraint in the future rather than force that lesson onto him.
He is also seen to be very good friends with Felicity Smoak and the two seem to have a sibling-like relationship. When Roy Harper was brought onto the team, he and John got along also with John providing a mentor-student relationship to Roy as well as Oliver.
Due to his time in the military, John is a disciplined and level-headed person who tries to approach everything with a calm demeanor, even in times of crisis. He has a sense of justice and honor, and is extremely loyal to the people he cares about, particularly his ex-wife Lyla Michaels whom he latter decides to remarry. Later on Lyla gives birth to his baby daughter (to John's amazement describing the experience of becoming a father as his whole universe changing) whom is named Sara in honor of John's good friend Sara Lance.
John is also able to isolate his emotions from his ability to think logically due to his time in the military. Instances where he does otherwise occur when Floyd Lawton was involved once he learns Lawton is who killed his brother. His hatred of Lawton is what lead to the dissolution of his relationship with Carly. However, after the two made a deal to save Lyla in Russia, he prescribed to his sense of honor in letting Lawton walk free as his end of the bargain. He also refused to let his vendetta get in the way of his principles of never leaving a man behind when they were partnered together in Task Force X. He also tried to talk Lawton out of his death wish while on a suicide mission by bringing up his daughter Zoe Lawton, and the chance to see her again one day, succeeding in doing so. He also later confessed that Lawton, the man who killed his brother showed much more character than Amanda Waller, the woman supposedly protecting the United States did during that mission. John's continued work with Lawton as well as the fact that Lawton has a daughter, to whom he provides money for with his job has had John experience a change of view of him, considering him something of a friend, or at the very least, a comrade. When Lawton sacrificed himself during the mission in Kasnia, so he and Lyla could return to their daughter, John made peace with Lawton's memory sharing a drink with Oliver with a toast, "to Lawton".
John is a man who stands by his principles and beliefs.
He has ever so viewed Oliver as his best friend, almost like a brother, and even had him as his best man at his second wedding to Lyla. However, when Oliver became "Al Sah-him" and kidnapped Lyla, leaving his daughter Sara alone, their relationship crumpled heavily, angering him to the point where he nearly beat a criminal to death. Despite Oliver attempting to explain to him that it was a ruse to prove his loyalty to Ra's al Ghul, John replied his action not only cost him John's friendship, but also his respect and trust. Ultimately, after having defeated Ra's, saved the city from the Alpha-Omega bioweapon together and seeing Oliver's genuine regret in his actions, John has come to at least be civil with Oliver, though he is still not ready to forgive him.
Few months later, after Oliver returns from retirement, and their lives were on the line, Oliver states that he understands that he had lost John's trust, but asks that John give him a chance to earn it back, which John does by sharing all the information about his brother's death with Oliver. Later on, after Oliver notes that John kept details of Andy's death from him for two years, John completely trusts Oliver once more when he jumped in front of an oncoming attack that was meant for John.
Upon learning of meta-humans and meeting the Flash, John is shocked, immensely disturbed; he finds it the hardest to comprehend the more other-worldly fantastical elements in the world in contrast to Oliver and Felicity. He claims that he'll never get used to seeing and experiencing the Flash's speed. He has stated on at least one occasion that he hates it when Barry super speeds him anywhere, having vomited at that time, and also tells Barry that his life was completely normal before he met the latter. He has stated to Oliver many times that they live in a crazy world.
John is not a hypocrite in his unforgiving nature as he treats everyone equally. He made no exception with his previously assumed deceased brother, Andy, and the new persona his brother exhibited. Even though Team Arrow volunteered to get Andy back, he was dead set against the idea. He cared more for the well being of his family in Team Arrow and only showed up to help liberate Andy from H.I.V.E. was because his brother, Oliver needed him.
- Peak of human physical condition: As a former soldier, bodyguard and vigilante, John is in top physical condition. He engages regularly in intense exercises and spars with Oliver Queen in the Arrowcave during his spare time. Due to his build and training he received from both his time in the military and training with Oliver, John is remarkably strong. Oliver even commented that his arms "are the size of bowling balls".
- Instinctive awareness: After entering his house with Felicity, John immediately felt something felt off.
- Extensive military training: John is well-trained in the armed forces disciplines, and has mentioned that he was once a part of Special Forces. He has considerable experience in live combat, having done three tours in Afghanistan.
- High-level intellect/Expert tactician/Leader: Due to his time in the military and with Team Arrow, John is an expert at formulating plans and executing them. John also plans ahead in case things don't go his way. When he was overhearing a conversation between Moira and Malcolm with a hearing device, he also had a pack of cigarettes and a lighter in his pocket in the event he was caught, which did happen, he pretended he was looking to have a smoke.
- Expert driver: John has the ability to drive multiple vehicles, and appears to be skilled at it. He is able to pursue enemies in various ways using different vehicles, known to be a car or a van. He jokingly refers to his penchant for driving during missions when calling "Black Driver" his secret identity.
- Expert marksman/Firearms: As a former soldier John is shown to be highly skilled with multiple types of firearms.
- Master hand-to-hand combatant/Martial artist: John is a highly skilled fighter, having developed his skills during his time as a soldier. He is skilled enough to match China White in combat and keep up with Oliver during their sparring sessions. His style appears to incorporate Wrestling, Muay Thai, Boxing, and Jiu-jitsu. Training with Oliver over the years have improved John's fighting skills, adding Wing Chun and Eskrima to his style. John is skilled enough to defeat multiple members of the League of Assassins, combining his firearms skills with his combat training, as well as take out multiple Shadowspire agents with ease, while unarmed.
- Expert military operator: As an ex-Special Forces soldier, John is well-versed in intelligence gathering, decoding ciphers and other coded messages, infiltration, and espionage.
- Expert stick fighter: John is an expert stick fighter. He has wielded an extendable baton as CQC weapon. He regularly trains with Oliver using sticks. In a training session, he and Oliver teamed up in a practice fight with Sara Lance, using bow staffs.
- Expert knife-fighter: John is an expert knife-fighter. When practicing Kali knife-fighting techniques with Oliver, John was able to keep up and was even complemented on his pace.
- Explosives expert: As a former soldier, John is highly skilled in planting and detonating explosives.
- Bilingualism: John is capable of fluently speaking English and Arabic.
- Skilled archer: John is shown to be a skilled archer, he is proficient in archery when he posed as the Arrow, however, John's archery skills are not at Oliver's level.
- Skilled pilot: John was trained to fly helicopters during his time as a soldier, and used this training to transport Arsenal and Black Canary during Danny Brickwell's takeover of the Glades.
- Skilled swordsman: Despite never been seen training with swords, John was able to defend himself for a while against Oliver in a sword duel.
- Weapons proficiency: John can handle most type of firearms, having been trained in the army. He is proficient enough in handling small caliber to high caliber firearms such as an assault rifle, grenade launcher or a sniper rifle. He is also capable of handling Oliver's bow and arrows, although not being as effective and efficient, as well as knives and sticks.
- Superhuman speeds: John is unable to tolerate it when Barry Allen super speeds him anywhere as he feels nausea and vomits repeatedly.
- Flick knife: Along with his sidearm, John also carries a small flick knife.
- Guns/Firearms: John primarily makes use of a pistol, wielding it quite effectively. He also is proficient in using assault rifles, sniper rifles, explosives and grenade launchers. After John became Spartan, he started using a custom pistol fitted with either bullets or darts, as seen when he shot Nyssa al Ghul. In Lost in the Flood, it is shown that this weapon has a grapple line that slows descent similar to Oliver's grapple arrows.
- Spartan helmet: After Oliver and Felicity left Starling City, John had a new helmet designed for him along with his new suit. The helmet seems to only cover the face and forehead, making it more of a concealment device rather than an actual helmet. The helmet also includes a tinted visor that can be retracted through unknown means. The helmet was later modified by Cisco Ramon, with John putting it on for the first time during Team Arrow's clash with Tobias Church.
- Spartan suit: Before Oliver and Felicity left Starling City, Queen recommended that John take up some form of identity concealment should he continue to regularly go into the field. John took his advice and had a new suit made for him. The suit seems to a more civilianized form of military armor. It includes a protective chestplate made of a leather-like material covered by a dark jacket likely made of the same material. The suit also includes dark Army pants and boots. The wrists include a device that can unload and load a firearm onto John's hand, allowing him to receive his sidearm quicker and carry more artillery at once. The helmet was later modified by Cisco Ramon, with John putting it on for the first time during Team Arrow's clash with Tobias Church.
- Arrow suit: John used Oliver's suits when needing to fake his identity as the Hood and the Arrow.
- Ski mask: Although John now does missions with Oliver's team with a mask, he sometimes used a ski mask in the past, to conceal his identity.
- Telescopic baton: John had been shown to use a telescopic baton, specifically when fighting Ravager.
- Old helmet: When John first became the vigilante Spartan, Cisco made him a helmet to go along with his suit, John wasn't apparently happy with the design as he admitted it could use improvements, he abandoned this helmet and was given a replacement.
DC's Legends of Tomorrow
- "Star City 2046" (mentioned)
Arrow: Season 2.5
- Blood part 11
- Blood part 12
- "Assault" Suicide Squad: Crisis in Kahndaq
- "Assurances" (mentioned)
- John is the only character (other than Oliver) on Arrow to appear in all episodes of the series.
- John has the distinction of being the first person Oliver shared his identity with and being the first person Oliver recruited into Team Arrow.
- In a currently erased timeline John, along with everyone in Central City, was killed by Vandal Savage using the Staff of Horus in his efforts to kill Carter Hall and Kendra Saunders. However, due to Barry Allen changing the time continuum this disaster never occurs.
- In another altered reality, he was killed by Damien Darhk or one of his two henchman. His mask was put on display in a trophy case along with many other vigilantes.
- John served as a member of Team Arrow longer than any other member of the team except for Oliver himself. He has been a member from An Innocent Man to Schism, and then again from Human Target to today.
- As seen in "Schism", John holds the rank of Master Sergeant in the United States Army, and has been awarded the Silver Star, two Defense Meritorious Service Medals, Meritorious Service Medal, Aerial Achievement Medal, three Air Force Commendation Medals, Air Force Achievement Medal, and numerous unit, campaign, and service awards.
- Despite serving in the Army, John's uniform displays numerous medals and service awards exclusive to the US Air Force.
Behind the scenes
- His surname Diggle is likely named after Andy Diggle, the author of Green Arrow: Year One, upon which Arrow first season is largely based, as is his brother who bears the exact name.
- John Diggle was later adapted to the mainstream Green Arrow comics starting with Issue 24 of the New 52s first series.
- Prior to his official secret identity being defined as Spartan, fans often jokingly referred to John's alter-ego as "Black Driver", referencing a line from John in "Identity".
- There is a running gag that John is the only one being seen freaked out towards super-powed characters such as the Flash and J'onn J'onzz from Supergirl.
- At the San Diego Comic-Con 2014, David Ramsey mentioned the possibilities of make an spin-off of Arrow featuring the members of the Task Force X in the lead roles, including John. However, co-producers Keto Shimizu stated that with the Suicide Squad film in development at that time, it doesn't seem it's like a possibility. It's currently unknown if this planned spin-off will be made in the future or not, because it was announced a sequel to the mentioned film, that could cause more delays.