<Li> Katie Cassidy as Siren - X </Li> <Li> David Ramsey as John Diggle / Spartan </Li> <Li> Victoria Askounis as young Caitlin Snow </Li> <P> The series was renewed for a fourth season on January 8, 2017, earlier than usual for the series . Executive producer Andrew Kreisberg said on this, "The great thing about our dear friends at The CW and Mark Pedowitz picking the shows up as early as they did has allowed us to start building the schedules for next season ." In May 2017, it was announced that Aaron Helbing would not return as an executive producer for season four, with only Greg Berlanti, Andrew Kreisberg, Sarah Schechter, and Todd Helbing returning from previous seasons . Todd Helbing and Kreisberg were slated to serve as the season's showrunners . In November 2017, Kreisberg was suspended from his role as executive producer and showrunner on The Flash over allegations of sexual harassment . By the end of the month, he had been fired, with his name eventually being removed from the credits from all shows he worked on . In addition, Berlanti would take additional responsibilities working with Helbing to co-showrun the season . </P>

Cast and crew of the flash season 4