Will Forte

Shaggy Rogers (voice)

Frank Welker

Scooby-Doo / Pterodactyl (voice)

Mark Wahlberg

Blue Falcon (voice)

Jason Isaacs

Dick Dastardly (voice)

Ken Jeong

Dynomutt, Dog Wonder (voice)

Amanda Seyfried

Daphne Blake (voice)

Gina Rodriguez

Velma Dinkley (voice)

Zac Efron

Fred Jones (voice)

Iain Armitage

Young Shaggy (voice)

Ariana Greenblatt

Young Velma (voice)

Mckenna Grace

Young Daphne (voice)

Pierce Gagnon

Young Fred (voice)

Kiersey Clemons

Dee Dee Skyes (voice)

Tracy Morgan

Captain Caveman (voice)

Simon Cowell

Simon Cowell (voice)

Kevin Heffernan

Bike Cop Gary (voice)

Christina Hendricks

Officer Jaffe (voice)

Henry Winkler

Keith (voice)

John DiMaggio

Restaurant Owner (voice)

Ira Glass

Ira Glass (voice)

Maya Erskine

Judy Takamoto (voice)

Billy West

Muttley (voice)

Don Messick

Muttley (archive sound) (voice)

Fred Tatasciore

Cerberus (voice)

Justina Machado

Jamie Rivera (voice)

Pam Coats

Mrs. Rogers (voice)

Tony Cervone

Ghost / Mr. Rigby / Alice (voice)