As an amateur, Doherty wins the Irish Amateur Championship twice (1987 and 1989), the IBSF World Under-21 Snooker Championship (1989) and the IBSF World Amateur Snooker Championship (1989). Having turned professional in 1990, Doherty wins a total of six ranking tournaments, including the 1997 World Snooker Championship in which he defeats Stephen Hendry of Scotland 18-12, inflicting Hendry’s first loss in a world final. This makes him the first and only player in the history of the game to be the world amateur, world under–21 and the world professional champion.
The following year, Doherty comes very close to breaking the Crucible curse, which refers to the fact that every first-time snooker world champion has failed to retain the title the following year. He reaches the final of the 1998 World Snooker Championship where he loses out to John Higgins of Scotland. He reaches his third final at the 2003 World Snooker Championship, but is narrowly defeated by Mark Williams of Wales. In other Triple Crown events, he is a three-time UK Championship runner-up (1994, 2001, 2002) and a two-time Masters runner-up (1999, 2000).
An intelligent tactician and prolific break-builder, Doherty has compiled more than 300 century breaks in professional competition. Since 2009, he has combined his playing career with commentating and punditry work.
Doherty currently represents an Irish poker site, appearing on radio commercials, and regularly playing in tournaments, where the players on the site receive a bonus for knocking him out.
In partnership with Sean Francis O’Donoghue and Karl Leon Paul, Doherty set up an online cue sports equipment-marketing company.
Doherty has been a World Professional Billiards and Snooker Association (WPBSA) player director since 2012.