Will Arnett Batman / Bruce Wayne (voice) Zach Galifianakis The Joker (voice) Michael Cera Robin / Dick Grayson (voice) Rosario Dawson Batgirl / Barbara Gordon (voice) Ralph Fiennes Alfred Pennyworth (voice) Jenny Slate Harley Quinn (voice) Mariah Carey Mayor McCaskill (voice) Channing Tatum Superman / Clark Kent (voice) Billy Dee Williams Two-Face / Harvey Dent (voice) Hector Elizondo Jim Gordon (voice) Conan O'Brien The Riddler / Edward Nygma (voice) Jason Mantzoukas Scarecrow / Jonathan Crane (voice) Doug Benson Bane (voice) Zoë Kravitz Catwoman / Selina Kyle (voice) Kate Micucci Clayface / Basil Karlo (voice) Riki Lindhome Poison Ivy / Pamela Isley (voice) Jonah Hill Green Lantern / Hal Jordan (voice) Adam DeVine The Flash / Barry Allen (voice) Eddie Izzard Voldemort (voice) Seth Green King Kong (voice) Jemaine Clement Sauron (voice) Ellie Kemper Phyllis (voice) David Burrows Anchorman Phil (voice) Ralph Garman Reporter #2 (voice) Chris Hardwick Reporter (voice) Chris McKay Pilot Bill (voice) Laura Kightlinger Reporter Pippa (voice) Todd Hansen Captain Dale (voice) Mark Jonathan Davis Richard Cheese (voice) Lauren White Chief O'Hara / Medusa / Additional Voices (voice)