Voice Type: Medium-High; Irish Accent

Kellie O'Sullivan is often the target of Shelly's bullying. The two girls had a falling out when Kellie's father went bankrupt and had to move the family into an apartment building. This has made Kellie one of the prime targets for the popular group to make fun of.

Kellie used to be an outgoing and social girl with dreams of becoming a 5-star chef. However, after Shelly's constant bullying she has become shy, withdrawn, and doesn't like socializing with anyone she doesn't trust. She barely has any friends but is often found tagging along with Kali (who is her next-door neighbor). She mostly spends any time when not in her classes in the home economics room as a way to isolate herself from Shelly and the school's main population.

Kellie is in Miss Deet's homeroom.