Born in Lancashire, England, Kieran O'Brien first rose to prominence as a child star on the BBC series Gruey (1988). He then enjoyed further success with a recurring role on the ITV series Children's Ward (1989). O'Brien continued acting into his adulthood, appearing regularly in Coronation Street (1960) and Cracker (1993).In 1999, he appeared in a full-frontal nude scene in Virtual Sexuality (1999). He appeared nude again in Burn It (2003) and then starred in 9 Songs (2004), a film by Michael Winterbottom which would push the boundaries of just how explicit a mainstream feature could be. Winterbottom knew O'Brien was the perfect casting opposite American model Margo Stilley, as he was a young actor both confident and well-endowed. He was required to be seen with a full erection, receiving a footjob from Stilley in a bath, performing vaginal sex with her and receiving oral sex from her. He also became the first mainstream British actor to be seen ejaculating on screen, while Stilley masturbated him, in a scene which was left uncut by the censors.Although O'Brien's role in such a controversial and groundbreaking sexually explicit film seems likely to be what people will always identify him with, he has continued to act, mainly in supporting roles on British television.