Frank Welker as Scooby-Doo / Rudy / Fred / Nefario (voice)

Grey DeLisle as Daphne / Daisy / Musketeer 1 / Olive (voice)

Matthew Lillard as Shaggy / Craggly / Captain Cutler (voice)

Kate Micucci as Velma / Helga (voice)

Myrna Velasco as Coco Diablo (voice)

Dee Bradley Baker as Esteban / Mr. Wickles / Cat Man (voice)

Jeff Bennett as Shady Guy / Charlie Humdrum / Hank (voice)

Anthony Carrigan as Trevor Glume / Farmer (voice)

Erin Fitzgerald as Library Kid / Superhero Girl / Musketeer 2 (voice)

David Lodge as Warden Collins / Harry the Hypnotist / Inspector (voice)

Lara Jill Miller as Prisoner Costume Teen / Superhero Boy / Musketeer 3 (voice)

Candi Milo as Prison Woman / Dinosaur Kid / Monster Kid (voice)

Jenelle Lynn Randall as Librarian / Superboy (voice)

Kevin Michael Richardson as Sheriff / Henry Bascombe / 10,000 Volt Ghost (voice)