Danielle Panabaker as Caitlin Snow: A bioengineering expert from S.T.A.R.
Colleen O'Shaughnessey as Grace Terrill.
Sunil Malhotra as Jacob: Ray's original lover.
Valdes also voices his Earth-1 counterpart.
Carlos Valdes as Cisco Ramon / Vibe of Earth-X: A member of the Freedom Fighters.
Whyte also voices his Earth-1 counterpart, Barry Allen / Flash.
Scott Whyte as Blitzkrieg: An alternate version of the Earth-1 Flash who is a member of the New Reichsmen on Earth-X.
Mercer also voices Oliver Queen / Green Arrow.
He is called Dark Arrow in " Crisis on Earth-X".
Matthew Mercer as Black Arrow: A member of the New Reichsmen that resembles Green Arrow, but is not the same as Dark Arrow.
Iddo Goldberg as Red Tornado of Earth-X: A member of the Freedom Fighters.
Melissa Benoist as Overgirl: An alternate supervillain version of Earth-38 Supergirl who is a member of the New Reichsmen on Earth-X.
Vadsaria also voices her Earth-X counterpart, Phantom Lady, who is a member of the Freedom Fighters.
Dilshad Vadsaria as Jenny Knight: A co-worker of Terrill's.
Mitchell also voices his Earth-X counterpart, Black Condor, who is member of the Freedom Fighters.
Jason Mitchell as John Trujillo: A co-worker of Terrill's that helps him learn about his new found powers.
Tovey also voices his Earth-X counterpart who is a member of the Freedom Fighters on Earth-X.
Russell Tovey as Ray Terrill / The Ray: A public interest advocate who gains light-based powers from his Earth-X counterpart and becomes a member of the Freedom Fighters on Earth-X.