The following is a list of main, recurring, and minor characters in the Disney Channel Original Series, Sonny with a Chance and its spin-off So Random!.
Main
Sonny Munroe
Allison "Sonny" Munroe (Demi Lovato). The newest member of comedy sketch TV show So Random!, She is from Appleton, Wisconsin. "Sonny" is Allison's nickname. Sonny used to dislike her nickname when she was little, but now she thinks it suits her.
Sonny is usually goofy and a bit childish, often admitting to do things that may seem strange to others. Friendly, sweet, and caring towards those around her, she is known as the nice girl of the group and does her best to help other people with their problems and achieve her dreams, but earns mixed results often due to some situations involving her meddling problems. She is shown to be talented at singing as well as playing the piano and guitar.
Sonny develops an on-and-off rivalry with Chad Dylan Cooper, and they become a couple in season 2 after Chad asks her out. She later breaks up with him due to his selfishness. In the series finale, it is hinted that Sonny still has feelings for him, though the fate of their relationship is left uncertain. Sonny is absent from the spinoff series So Random! due to Demi Lovato leaving the cast for health reasons; Sonny's absence is never explained.
Tawni Hart
Tawni Hart (Tiffany Thornton). Tawni is obsessed with fashion, pink, and herself. She becomes upset if she does not get her way. In the beginning, Tawni was openly jealous of Sonny to the point that she committed mail fraud by stealing all of Sonny's fan mail, but later grew more accepting of her as a member of the show.
Tawni is probably the only person who initially knew about Sonny and Chad's mutual feelings for each other, but never mentioned it to anybody. Tawni has a secret - she likes Sonny. She is jealous of Sonny's fans. Despite their rocky beginnings, she has since begun to care about Sonny as a friend and eventually as a best friend.
She is often seen giving her advice and is shown to be nicer than before, such as the instance of driving Sonny all the way back to Wisconsin in "Sonny with a Secret", but she tells Sonny to do projects for her, shown in "Falling for the Falls (Part 1)". Also, she still doesn't like it that Sonny's boyfriend is Chad, as do all of the So Random! cast. She has been on So Random! for five years. She says that she was homeschooled, and that her mother Tammy (also her manager) was very strict.
Chad Dylan Cooper
Chad Dylan Cooper (Sterling Knight). He is the teen heart-throb of Tween Weekly and Mackenzie Falls. He is the arch-rival of Sonny and the cast of So Random! early in the series, as well as Sonny's love/hate interest as developed later. He seems to have liked Sonny since the beginning of the show, and in one episode tries to force her to kiss him, before they were dating.
He is a bratty egomaniac and thinks that he the "greatest actor of his generation", and can be seen as effeminate in his obsession with his own appearance. Despite this selfish and childish behavior, he has moments where he shows he is kind and deep, especially when he's around Sonny. He became more friendly towards the cast of So Random! because of his feelings towards Sonny, and later, he eventually falls in love with her and starts dating her. However, in "My Two Chads", it is revealed that Chad has a stunt double named Chaz, who he has to go on dates with Sonny that he deems dangerous. When Sonny finds out about this, she dumps him, but they get back together at the end.
In "Sonny with a Choice", when he discovers that So Random! won the Tween Choice Awards, his ego and jealousy get the better of him, leading him to recount the votes so that Mackenzie Falls wins instead, which he later tells Sonny. Sonny is disgusted at his inability to put others before himself, causing them to break up for good. In "New Girl", it is revealed that he still has feelings for Sonny. Sonny writes a song about him and hums it at the end, hinting that she still has feelings for him as well. He later joins So Random! when Sonny leaves the show. It is known he is still in Mackenzie Falls even after he joins So Random!
Nico Harris
Nico Harris (Brandon Mychal Smith). One of the primary cast members of So Random!, Nico is Grady's best friend and they always do pranks and wacky things together. He and Grady attempt many pranks but they often fail because (in Tawni's words) they are "full of loud music, bad choreography and things being thrown" as they often copy the movies. The two are shown to be a little immature. He always comes up with ideas that later turn crazy.