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 stimulated his penis with her hand, 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.