Buddy Boy is a 1999 psychological thriller film written and directed by Mark Hanlon and starring Aidan Gillen, Emmanuelle Seigner and Susan Tyrrell.

Rex Reed of The New York Observer called it "a curious, unsettling, darkly conceived and absolutely fascinating little film.

"[2] The film's title character, Francis, lives with his invalid, abusive mother Sal in a dingy tenement apartment, and has suffered a life of unrelenting misfortune and brutality, further impacted by a stutter.

Buddy Boy premiered to a standing ovation at the Venice International Film Festival on September 5, 1999 in the Cinema del Presente section.

On September 11, 2007, Buddy Boy was released as part of a three-film DVD triptych along with Antonia Bird's Face and Peter Medak's Let Him Have It.