When the Justice League goes missing and villains overrun Metropolis, there's only one team that can solve this mystery: Scooby-Doo and the gang! But wait, there's a new dog in town – Krypto – Superman's Superdog with Super Powers. Mystery Inc. will need all the help it can get when phantoms menace the Justice League's headquarters.
| Actor | Role |
|---|---|
 Frank WelkerScooby-Doo / Fred Jones (voice) | Scooby-Doo / Fred Jones (voice) |
 Grey DeLisleDaphne Blake / Wonder Woman (voice) | Daphne Blake / Wonder Woman (voice) |
 Matthew LillardShaggy Rogers (voice) | Shaggy Rogers (voice) |
 Kate MicucciVelma Dinkley (voice) | Velma Dinkley (voice) |
 P.J. ByrneJ.B. (voice) | J.B. (voice) |
 Victoria GraceMercy (voice) | Mercy (voice) |
 Charles HalfordLex Luthor (voice) | Lex Luthor (voice) |
 Nolan NorthComputer / Joker / Superman (voice) | Computer / Joker / Superman (voice) |
 Tara StrongHelen / Lois Lane / Harley Quinn (voice) | Helen / Lois Lane / Harley Quinn (voice) |
 Fred TatascioreSolomon Grundy / Perry White (voice) | Solomon Grundy / Perry White (voice) |
 James Arnold TaylorJimmy Olsen / Rex Ruthor (voice) | Jimmy Olsen / Rex Ruthor (voice) |
 Niccole ThurmanMayor Flemming (voice) | Mayor Flemming (voice) |