Kevin Gerrity is the husband of Corrine Maloney, the father of Julian McGrath-Gerrity and a friend of Sonny Koufax. Kevin is played by Jon Stewart. While he is not in the film much (and did not even appear in the trailers), he is a crucial character because the plot and its eventual resolution hinges on Sonny being mistaken for him.
- Not much is known about Kevin's upbringing, but it is presumed to have been very normal: Kevin is characterized as an Everyman hero who is not perfect, studying hard in college and becoming successful, but goofing off every now and then. At some point Kevin met his future wife, Corrine. He also moved into an apartment in New York with Sonny Koufax. Kevin studied at Syracuse University along with Sonny, Phillip D'Amato, Tommy Grayton and Mike.
- The climax of the film reveals Kevin to be brave and compassionate. He is willing to sacrifice his relationship with Corrine to save Sonny from jail, revealing the illegitimate son he never told her about. But Corrine forgives him, and Sonny is pardoned from prison on the condition that he release Julian to Kevin's custody.