Comic-Con: The Flash season 5 trailer moves forward During the panel at San Diego Comic-Con, The CW released the first The Flash season 5 trailer which you can watch in the player below. Season 5 of The Flash premieres on Tuesday, October 9, on The CW. Also confirmed at the panel was the addition of Chris Klein (American Pie) as this season’s new big bad, Cicada Matching wits with The Thinker, who by season’s end had harnessed the powers of all twelve bus metas he created, stretched Team Flash to their limits, but with the help of some new allies, Barry Allen (aka The Flash) and company were able to put a stop to the Enlightenment and save Central City once again.