Marinelli attended the American Academy of Dramatic Arts in New York City to study acting. He first started acting in 1991 and his first film role was in Jumpin' at the Boneyard. He later went on to act in several television series with recurring roles in both Falcone and That's Life. In 2001, he played the role of mobster John Gotti in the television movie Boss of Bosses. He also voiced the character Henry Tomasino in the 2010 video game Mafia II and went on to provide additional voices in Mafia III. Marinelli is also a founding member of the Actors Gym Theater Company along with Robert Moresco.