The Flash, Supergirl, Arrow, and DC's Legends of Tomorrow will be teaming up for an Invasion.
It appears that The Flash's crossover episode for Season 3 will be directed by Dermott Downs.
Preview trailer for the Flash and Supergirl crossover episode "Worlds Finest"
CBS has released official photos from the Supergirl episode "Worlds Finest" with Grant Gustin as The Flash.
Preview images for the Flash episode "King Shark" featuring Diggle and Lyla from Arrow
Promo trailer for The Flash episode "King Shark" featuring Arrow's John Diggle and Lyla Michaels
The Flash Grant Gustin has shared a photo of himself with Supergirl Melissa Benoist.
David Ramsey and Audrey Marie Anderson from Arrow guest star in the Flash episode "King Shark."
Felicity and Ray from Arrow will be visiting The Flash in Episode 18.
The CW will be re-airing the Flash and Arrow crossover.