Adam Sandler as the President of Station Square, Tina Fey as the President's Secretary, Paul Giamati as Dr. Eggman (costume that looks just like Dr. Eggman's outfit in the game series with a stick on mustache), Emma Watson as Princess Elise (costume that looks just like Princess Elise's outfit in the 2006 game), Elle Fanning as Maria Robotnik (in flashback memories), Tim Curry as Gerald Robotnik (in flashback video clips), Patton Oswalt as Sonic the Hedgehog/Supersonic (voices, ever since Remy's voice in Ratatouille (2007)), Ben Stiller as Knuckles the Echidna (voice, ever since Alex the Lion's voice in the Madagascar movie series), Katie Leigh as Miles "Tails" Prower the 2 Tailed Fox (voice, ever since Honker Muddlefoot's voice on Darkwing Duck), Jason Marsden as Shadow the Hedgehog/Super Shadow (voices, ever since Kovu's voice in The Lion King 2: Simba's Pride), Jennifer Hale as Amy Rose (voice, ever since Mandy's voice on Totally Spies!), Andrea Libman as Cream the Rabbit (voice, ever since Young Chi-Chi's voice on Dragon Ball Z), John Goodman as Vector the Crocodile (voice, ever since the T-Rex's voice in We're Back: A Dinosaur's Story), Matthew Fox as Espio the Chameleon (voice, ever since Racer X's voice on Speed Racer), Russi Taylor as Charmy Bee (voice, ever since Timmy Tantrum's voice in the Teen Titans season 5 episode: "Hide and Seek"), Richard Kind as Big the Cat (voice, ever since Bing Bong's voice in Inside Out (2015)), Sandra Bullock as Rouge the Bat (voice, ever since Miriam's voice in The Prince of Egypt (1998) and Scarlett Overkill's voice in Minions (2015)), Kath Soucie as Sally Acorn (voice), Tara Charendoff as Bunnie Rabbot (voice), Corey Burton as Mephiles the Dark (evil sounding voice), Frank Welker as E-123 Omega (robotic voice), Mr. T as E-102 Gamma (robotic voice), Dan Green as Bark the Polar Bear (voice), Jim Parsons as Bean the Dynamite (voice), Seth Green as Fang the Sniper (voice), Nika Futterman as Sticks the Badger (voice), Jesse McCartney as Silver the Hedgehog/Super Silver (voices, ever since Roxas's voice in the Kingdom Hearts game series), Penelope Cruz as Blaze the Cat (voice, ever since Juarez's voice in G-Force (2009)), Selena Gomez as Mina Mongoose (voice), Jason Liebrecht as Mighty the Armadillo (voice), Veronica Taylor as Tikal the Echidna (voice, in flashback memories), Ryan Drummond as Scourge the Hedgehog, Sonic's evil counterpart (voice), Bindi Irwin as Marine the Raccoon (voice) and Amy Birnbaum as Cosmo the Seedrian and Froggy (voices, if Cosmo the Seedrian ever returns to the new Sonic series)