[citation needed] The California Boxing Hall of Fame has listed O'Halloran as one of its inductees of the 2009 HOF class.

He first won the role of ex-convict Moose Malloy in the 1975 film Farewell, My Lovely, featuring Robert Mitchum as private eye Philip Marlowe.

O'Halloran criticized Alexander and Ilya Salkind, the producers of the Superman films, for their mishandling of the franchise, believing that their firing of director Donner was a huge blow to the series and the cause of its downturn in quality, a sentiment that was shared by Gene Hackman, who refused to reprise his Lex Luthor role in the third film, and by Margot Kidder who played Lois Lane.

[citation needed] In an interview with Starlog Magazine in 2006, O'Halloran stated that he and Christopher Reeve did not get along during the making of Superman II.

[11] O'Halloran has also played supporting roles in King Kong (1976), March or Die (1977), The Baltimore Bullet (1980), Dragnet (1987), Hero and the Terror (1988), Mob Boss (1990), The Flintstones (1994) and Dagon Troll World Chronicles (2019).

The book also outlines O'Halloran's relationship with his alleged father, a former boss of the Gambino crime family, Albert Anastasia.