Gregory Cupoli is an American actor known for character roles across live-action television, film, and voice acting. He was born and raised in the suburbs of New Jersey and trained under William Esper at the Mason Gross School of the Arts at Rutgers University, where he earned a Bachelor of Fine Arts in Acting. His thesis performance was the role of Tajomaru in a stage production of Rashomon, a performance that received positive critical praise. During the summer of 1981, while performing with the Rutgers Theatre Company, he created the role of Fifi LaBella in the English language premiere of Luigi Pirandello's Cap and Bells.

Cupoli moved to Hollywood in 1990 and soon earned his Screen Actors Guild card with a role on the television series Major Dad. His first studio film appearance came in 2000 when he portrayed a male role model for Mel Gibson's character as a child in What Women Want. Over a career spanning several decades, he has appeared in numerous television series including Everybody Hates Chris, Chelsea Handler's After Lately, and the daytime dramas Days of Our Lives and Passions.

In the field of voice acting, Cupoli provided the voice for the character Mr. Frog, a thug, in the 2010 French animated film Une vie de chat, also known as A Cat in Paris, which received an Academy Award nomination for Best Animated Feature. More recently, he joined the English voice cast for the anime series Leviathan, the Netflix adaptation of Scott Westerfeld's steampunk trilogy. In this production, he voices the character Klopp, whose full name is Otto Klopp. The English dub for Leviathan was announced in July 2025, with Cupoli featured among a cast that includes Broghanne Jessamine, Dor Gvirtsman, Rob Nagle, Michelle Lukes, and Christopher W. Jones.