Will Forte

as Shaggy Rogers (voice)

Mark Wahlberg

as Blue Falcon (voice)

Jason Isaacs

as Dick Dastardly (voice)

Gina Rodriguez

as Velma Dinkley (voice)

Zac Efron

as Fred Jones (voice)

Amanda Seyfried

as Daphne Blake (voice)

Kiersey Clemons

as Dee Dee Skyes (voice)

Ken Jeong

as Dynomutt (voice)

Tracy Morgan

as Captain Caveman (voice)

Frank Welker

as Scooby-Doo / Pterodactyl (voice)

Iain Armitage

as Young Shaggy (voice)

Mckenna Grace

as Young Daphne (voice)

Pierce Gagnon

as Young Fred (voice)

Ariana Greenblatt

as Young Velma (voice)

Simon Cowell

as Simon Cowell (voice)

Christina Hendricks

as Officer Jaffe (voice)

Henry Winkler

as Keith (voice)

Harry Perry

as Harry Perry (voice)

John DiMaggio

as Restaurant Owner (voice)

Kevin Heffernan

as Bike Cop Gary (voice)

Ira Glass

as Ira Glass (voice)

Henry Kaufman

as Chad / Chet (voice)

Maya Erskine

as Judy Takamoto (voice)

Billy West

as Muttley (voice)

Don Messick

as Muttley (archive sound) (voice)

Fred Tatasciore

as Cerberus (voice)

Justina Machado

as Jamie Rivera (voice)

Kennedy Peil

as Indira Knight (voice)

John McDaniel

as Hal Murphy (voice)

Ryan Folsey

as Beach Guy (voice)

Pam Coats

as Mrs. Rogers (voice)

Tony Cervone

as Ghost / Mr. Rigby / Alice (voice)

Adam Sztykiel

as Officer Casey (voice)

Alex Kauffman

as Officer North (voice)

Vanara Taing

as Baby Rotten (voice)

Sarah Lancia

as Dispatcher Stevens (voice)

Maven Morgan

as Kari (voice)

Eric Cowell

as Ben (voice)

Michael Kurinsky

as Samuel Colton (voice)