Sam Sandwich - The main protagonist of the mini-series, he's a hero sandwich and always stops his foes from serving bad food in his town. He is voiced by Wally Wingert, who portrays Orbot in the Sonic the Hedgehog video games.
Salad Lad - He's Sam Sandwich's sidekick, he makes inventions to help Sam stop his enemies, Sam's nickname for him is "Sal". Voiced by Scott Menville.
David - He's the only human in the miniseries, and thus the only character portrayed in live-action instead of stop motion. In every single episode, when he notices something unhealthy or suspicious about his food or something odd about food and drinks, he communicates with Sam and Sal on the Giant Video Screen.
Sweet Tooth - She's a sweet but sinister villain who wants kids to eat lots and lots of sugar, she has a cupcake for a head. She speaks with a southern drawl, has enormous lips, and wears a frumpy polka-dotted shirt. Sam Sandwich always refers to her as his "cupcake cranimued nemesis", implying she is Sam's main, or at least most powerful enemy. Voiced by Cree Summer.
Fry-Borg - He's a giant robot who wants kids to eat deep fried food. He keeps his gears greased with oil, without it, Fry-Borg immediately shuts down. He has large, bulbous eyes.
Salty Pup - He's a pirate pup who wants kids to eat salty food, he has a pirate ship with its body shaped like a salt shaker.
Big Cheese - He's a cheesy villain who wants kids to eat mega-sized meals, his head is literally "big cheese".