Frank Welker

as Scooby-Doo / Fred Jones (voice)

Matthew Lillard

as Shaggy Rogers (voice)

Grey DeLisle

as Daphne Blake (voice)

Mindy Cohn

as Velma Dinkley (voice)

Julie Bowen

as Dr. Devon Albright (voice)

Lacey Chabert

as Melanie Staples (voice)

Alan Rachins

as Dr. Ned Staples (voice)

Paul Reubens

as Irv (voice)

Phil LaMarr

as Stan (voice)