Ben Schwartz as Sonic the Hedgehog

Jack Dylan Grazer as Alberto Scorfano

Jacob Tremblay as Luca Paguro

Rosalie Chiang as Meilin Lee

KiKi Layne as Ellie Steckler

Will Arnet as Sweet Pete

Keegan-Michael Key as frog co-worker and Bjornson the record dealer

Tim Robinson as Ugly Sonic

Seth Rogan as Bob the Viking, B.O.B, 2019 Pumbaa and Mantis

Flula Borg as DJ Herzogenaurach

J.K Simmons as Captain Putty

Da'Vone McDonald as Jimmy the Polar Bear

Akiva Schaffer as Animal Squad director, ET, Officer Sock Puppet, Happy Cartoon Dog, Shoeshiner, Mr. Natural, Hungry Mouse and Officer Chameleon

Rachel Bloom as Insurance Sheep, Flounder, Flower Girl, Black & White Reporter, Lost Boy, Stinsons Boy and Banzai Bill

Liz Cackowski as Cow Teacher, Tigra and Officer O'Hara

(aand too many to list here so i'm gonna leave it at that)