- "Extraordinary. The power he possesses, it's like the—it's like the Gods of old. It's like Mercury on earth. Can you imagine if you could control his power? If you could—if you could harness it? You could change what it means to be human. The man in a red mask is the key, and I'm gonna get him."
- —Simon Stagg to Harrison Wells about The Flash[src]
Simon Stagg (died October 13, 2014) was the CEO of Stagg Industries. Although he had built a careful reputation and facade as a philanthropist, Stagg appeared to be driven by ambition and greed in almost equal measure. Stagg was fascinated by "the man in the red mask", and his potential implications for humanity, though this fascination eventually led to his death.
At some point of time, Simon Stagg attended Central City University in his youth. He was recognized by the university, which later led to him becoming the regents' choice for man of the year for his work on organ transplants.
Attack by Danton Black
Simon was being honoured at Stagg Industries for his work in organ transference, being named man of the year by Central City University. He thanked everyone and began to leave, refusing to give Iris West a quote for her article. A squad of men stormed the event with guns, looking for Simon, however he'd already left. Sometime later, detectives Joe West and Eddie Thawne came to Stagg, asking about a potential suspect of theirs, Danton Black, though he claimed that Black was merely a biogeneticist, not a killer. 
As Simon farewelled the detectives, the group of men appeared again; and unbeknownst to Stagg, they were in fact all Multiplex and his "clones". He was rushed off by Eddie, though Joe was shown the true nature of their identities shortly after. Following their encounter, Joe urged reconsidering protective custody, though Stagg reassured that he'd upped his security. He greeted the arriving Harrison Wells, sarcastically suggesting not to get up for him, and returned to Stagg Industries. Later that night he finally came face to face with Danton. Before he could be shot, Barry Allen, in his suit, sped through, grabbed him and told him to stay in his office. Barry ultimately beat Black . Simon sat in his office through the night, when he was visited by Wells. They began discussing Simon's savior, as if he was "Mercury on earth". Stagg suggested that there were possible major implications if they could find and harness the man's power. However, wishing to protect the man who would come to be known as "The Flash", Wells stood up from his wheelchair and stabbed Stagg, killing him.
After Simon was killed by Eobard Thawne (under the guise of Harrison Wells) the majority of the public (the ones who were aware of his true nature) were completely unfazed by Simon's death; due to his arrogant, greedy, selfish and immoral traits.
While effectively appearing humble and kind, working hard to appear as a humanitarian and philanthropist to the public, Simon was none of these things. Rather, the opposite was true; in reality, he was arrogant, greedy, selfish and immoral. He was known to steal people's research, or take credit for their work; because of this he had been sued at least 20 times.
When Simon discovered the existence of the Flash, he planned to exploit Barry's powers, proudly admitting this to Eobard Thawne (under the guise of Harrison Wells) a reckless action which cost him his life at the hands of the latter; technically Simon still got exactly what he deserved (in a bad way) when he was killed by Eobard.
Behind the scenes
- In the DC comics, Simon Stagg is the amoral founder and CEO of Stagg Enterprises/Industries and a minor villain. He is notable for being the man responsible for the creation of the superhero Metamorpho, The Element Man, whom he was attempting to kill. He acts as Metamorpho's archenemy.