Jeremy Sullivan was a classmate and friend of both Cory and Topanga when they all attended Jefferson Elementary and John Adams High School together. He was a background character throughout the first five seasons of the series.
- His surname of Sullivan was revealed in Cory's Alternative Friends, when Cory tries to team with him after Mr. Feeny reasssigns Shawn with Minkus, but the teacher claims that would be worse than his original teaming with Shawn, and instead selects Topanga as Cory's new partner.
- His only line in the series (as Costumed Kid #3) was in Boys II Mensa.
- His first name, Jeremy, was revealed in Band on the Run, as he takes Topanga to the dance, after Cory tells her that he is fine with her going with someone else.