Melissa O’ Malley is the self-proclaimed most popular girl in school, and serves as the main antagonist to June and her friends, especially Jody and Ophelia. She has a stuck-up snobby attitude and is extremely self-absorbed, always wanting to be the center of attention. She is also a spoiled, rich, mean-queen. She is constantly causing problems for June such as trying to win over Marcus's affection at the school dance and running opposite to her at the class president election, often insulting or causing distress to June's friends in the process.
She is voiced by Tara Strong.
Melissa O' Malley is shown to be an antagonistic queen bee of the school. She is shown to be very petty and willing to do anything to annoy or belittle other kids, especially Jody, Ophelia, June and their friends.