- Grant Gustin as Barry Allen/The Flash
- Candice Patton as Iris West
- Danielle Panabaker as Dr. Caitlin Snow
- Carlos Valdes as Cisco Ramon/Vibe
- Keiynan Lonsdale as Wally West/Kid Flash
- Tom Cavanagh as Dr. Harrison "Harry" Wells and TBA
- Jesse L. Martin as Detective Joe West
- Neil Sandilands as Clifford DeVoe/The Thinker
- Hartley Sawyer as Ralph Dibny/Elongated Man
- Kim Engelbrecht as "The Mechanic"
- Danny Trejo as "Breacher"
- Jessica Camacho as Gypsy
- Anne Dudek as Tracy Brand
"Running up against an evil time remnant version of yourself is something no one should ever have to do, but that’s exactly what faced Barry Allen (aka The Flash) as he fought to save the life of fiancée Iris West from the God of Speed known as Savitar."
"Barry’s victory was short-lived, however, as an unbalanced Speed Force began to wreak havoc on Central City, forcing Barry to sacrifice himself for the greater good."
"With The Fastest Man Alive now trapped inside an extra-dimensional energy, and unknown dangers lurking in the shadows, it will be up to Team Flash to free Barry from his own personal Hell."
Confirmed plot points
- The main villain this season will not be a speedster.
- The main villain will be DeVoe, who was mentioned in the previous season by Abra Kadabra and Savitar.
- There will be a four-way crossover with Supergirl, DC's Legends of Tomorrow and Arrow.
- The crossover will take place over two-nights and will consist of 2 "two-hour miniseries". The first "two-hour miniseries" will consist of Supergirl and Arrow while the second one will consist of The Flash and DC’s Legends of Tomorrow.
- The crossover will have high emotional stakes and emotional payoffs with romance in the air.
- The season premiere will take place 6 months after the Season 3 finale.
- Iris will step into the role as the leader of Team Flash.
- Wally will not take on the mantle of the Flash.
- Kid Flash, Vibe, and Joe will battle a samurai like villain in the season premiere.
- Wally will wear Barry's suit this season.
- Shawna Baez/Peek-a-Boo will return this season.
- A superhero from the DC Comics called Elongated Man will make a recurring appearance throughout this season.
- A villain named The Mechanic will be a recurring character this season who builds devices for DeVoe.
- Gypsy's father will be introduced.
- Tom Felton will not return, thus Julian Albert will not be a part of Team Flash this season.
- Harrison "Harry" Wells will be a part of the season but another version of Harrison Wells might show up.
- Kid Flash and Vibe pick up the job that Barry left behind.
- Cisco will return to a more lighthearted joking manner.
- Even though Barry will come back from the Speed Force, it might not be the "same" Barry that went into it.
- Tom will direct at least one episode this season.
- Barry will get a new suit that resembles the 2024 suit he saw when he met his future-self in 2024.
- Tracy Brand will return at some point but she won’t necessarily be a full-fledged member of Team Flash.
- A villian named Hazard will appear in the third episode.
- Barry will get out of the speed force in the first episode.
Confirmed new characters
- Clifford DeVoe/The Thinker: After being struck with dark matter from the particle accelerator explosion, Clifford DeVoe became a meta-human with a mega-mind. A Stephen Hawking-esque genius who's devised an intricate plan to fix all that he deems wrong with humanity. "The Thinker" will embark upon a season long battle with the Flash that pins the "fastest man alive" against the "fastest mind alive".
- Ralph Dibny/Elongated Man: Ralph has the ability to stretch his body to super-human lengths and sizes... however, while resculpting his old body is easy to do, Dibny finds losing the old misguided sense of truth and slobbery, even after joining the team at S.T.A.R. Labs, is a far more difficult task to accomplish.
- The Mechanic: An extremely intelligent engineer who will design devices for Clifford DeVoe. Basically, DeVoe's right hand. She’ll support Devoe no matter the consequences.
- Breacher: Earth-19 bounty hunter Gypsy's imposing father. Also a feared bounty hunter, he seeks to prevent any inter-dimensional traveler from threatening life on his planet - especially his daughter's.
- Rebecca Sharpe/Hazard: Perpetually down-on her luck and is convinced her life is cursed — until a freak accident changes everything. With the universe on her side, she poses a threat to both Team Flash and Central City.
|#||Episode name||Directed by||Story by||Teleplay by||Original airdate|
|1||"The Flash Reborn"||Glen Winter||TBA||TBA||October 10, 2017|
|3||"Luck Be A Lady"||TBA||TBA||TBA||TBA|
|4||"Elongated Journey Into Night"||TBA||TBA||TBA||TBA|
- ↑ 1.0 1.1 1.2 CW Loads Up Fall Schedule Rollout Across One Week in October - Variety
- ↑ The CW renews seven series including 'Arrow,' 'The Flash,' 'Supernatural' and 'Crazy Ex-Girlfriend' - LA Times
- ↑ 3.0 3.1 3.2 3.3 3.4 3.5 3.6 The CW Releases Fall Season Synopses for 'Arrow', 'Flash', 'Supergirl' & More - CBR.com
- ↑ 4.0 4.1 4.2 4.3 4.4 ‘The Flash’ Cast on Season 4, Barry’s Return, and Killer Frost’s Future - Collider
- ↑ 5.0 5.1 5.2 5.3 5.4 The Flash Casts Villainous Thinker, Adds Danny Trejo as (Spoiler)'s Dad - TVLine
- ↑ 'The Flash' Casts Iconic Justice League Member For Season 4 - Comicbook.com
- ↑ 7.0 7.1 7.2 7.3 7.4 7.5 'The Flash' season 4 spoilers: The Mechanic, Elongated Man reportedly coming - http://cartermatt.com
- ↑ Jessica Camacho To Recur In Flash Season 4 - FlashTVNews
- ↑ 9.0 9.1 ‘The Flash’ Spoilers: Is Anne Dudek Returning For Season 4? - ibtimes.com
- ↑ The Flash Season 4 SDCC Panel Info Released - Comicbook.com
- ↑ 11.0 11.1 'The Flash' nixes speedster villain in season 4 - EW
- ↑ 'The Flash' Scoop: Season 4 Villain Is Exactly Who You Think It Is - TV Line
- ↑ 13.0 13.1 CW sets two-night event for four-way superhero crossover - Entertainment Weekly
- ↑ 14.0 14.1 ‘The Flash’ Star Candice Patton On Iris West’s New Role In The Team - Heroic Hollywood
- ↑ Kid Flash Actor Keiynan Lonsdale: Wally West Will Not Become The Flash In Season 4 - Heroic Hollywood
- ↑ 'The Flash' Season 4: Vibe and Kid Flash Battle the Premiere Villain - Blasting News
- ↑ Canadagraphs (@canadagraphs) - Twitter
- ↑ Canadagraphs (@canadagraphs) - Twitter
- ↑ WonderWoman (@ThemysciraBound) - Twitter
- ↑ 'The Flash': Tom Felton not returning as series regular - EW
- ↑ - Youtube
- ↑ The Flash' Gets a New Suit in Season 4 Set Photo - Comicbook.com
- ↑ 23.0 23.1 ‘The Flash’ Casts Sugar Lyn Beard as Hazard (EXCLUSIVE) - Varirety
- ↑ - Youtube
- ↑ 25.0 25.1 “The Flash Reborn” To Be Directed By Glen Winter - FlashTVNews
- ↑ 26.0 26.1 26.2 - SpoilerTV
- ↑ ‘The Flash’ Season 4: Is DC Villain Hazard Appearing In Episode 3? - International Business Times
|The Flash season 4|
|"The Flash Reborn" • "Mixed Signals" • "Luck Be A Lady" • "Blood Will Run" • "Emergency Stop" • TBA • TBA • "Greater Threat"|