Born March 21, 1975
Lives Cwm, Gwent, Wales
Nickname "Sprog"
Turned pro 1992 
Match stats 1998/99 ranking events; 1999/2000 ranking events 
Highest pro break 147 (2005 Embassy World Championship)
Highest ranked 1 (2000-2001, 2003)
World Championship best Winner two times (2000 and 2003) 
Best ranking event performance Winner of 16 tournaments: Regal Welsh 1996, 1999; Grand Prix 1996; British Open 1997; Irish Open 1998; Thailand Masters 1999, 2000, 2002; UK Championship 1999, 2002; Embassy World Championship 2000, 2003; Grand Prix 2000; China Open 2002, 2006; LG Cup 2003 
Major invitation tournament victories:  Benson & Hedges Masters 1998, 2003 
Career centuries 54 (end of 1997/98 season)
Career earnings ￡1,847,453 (through the 2001 Thailand Masters)
2000/2001 earnings ￡225,440 (through the Thailand Masters)
Speciality Potting
Achievements Mark J Williams broke into the snooker elite in the 1995/96 season. In that year he won his first major tournament, the 1996 Welsh Open. In 1998 he won the Benson & Hedges Masters by beating Stephen Hendry on a respotted black in the final.
In the 1998/99 season he won three ranking tournaments; the 1998 Irish Open, the 1999 Welsh Open and the 1999 Thailand Masters. This makes him only the fourth player in history to win three ranking titles in one season. Steve Davis, Stephen Hendry and John Higgins are the other three players to have managed this feat.

In 2000 he finally became world champion by beating long-time friend and rival, Matthew Stevens 18-16 in the final after being behind the entire match. In 2003 he won it again.

Another important title was the 1999 Liverpool Victoria UK Championship.

In total he's been in 33 professional finals.

Previously he has also won the 1994 Benson & Hedges Championship.

Until going down 9-7 to Fergal O'Brien in the 2003 Travis Perkins UK Championship Mark Williams won his first match in 48 straight ranking tournaments!