Seth Green
The Nerd / Batman / Robin / Scarecrow / Darkseid / Ace the Bathound / Toyman / Dr. Fate / Jimmy Olsen / Black Manta / Aquaman / Clayface / The Penguin / Killer Croc / Cyborg / Banehound / Various (voice)

Breckin Meyer
Superman / Bizarro (voice)

Nathan Fillion
Green Lantern / Black Adam (voice)

Alex Borstein
Wonder Woman (voice)

Matthew Senreich
The Flash / Reverse-Flash / Weather Wizard / Waiter (voice)

Alfred Molina
Lex Luthor / Green Arrow (voice)

Zac Efron
Superboy / Brainiac (voice)

Sarah Hyland
Lena Luthor (voice)

Clancy Brown
Gorilla Grodd (voice)

Paul Reubens
The Riddler / Sunbather (voice)

Giovanni Ribisi
The Joker / Two-Face (voice)

Kevin Shinick
Narrator / Starro / Captain Cold (voice)

Zeb Wells
Sinestro / Swamp Thing / Captain Cold (voice)

Tara Strong
Harley Quinn (voice)

Hugh Davidson
Martian Manhunter / Seahorse Leader (voice)

Clare Grant
Catwoman / Poison Ivy / Little Girl (voice)