Martyn Elwyn Williams, MBE (born 1 September 1975) is a Welsh former professional rugby union player who played as a flanker.

Overall, he played 17 times for the Lions across the 3 tours scoring 2 tries which included 4 test matches (NZ and SA*3).

Williams played club rugby for Pontypridd, with whom he won the 1996–97 Welsh league, then moved to Cardiff RFC in 1999.

Williams announced his retirement from international rugby on 1 October 2007, following Wales' early exit from the 2007 Rugby World Cup only to make a surprise decision to return to international action when he was recalled by new Wales head coach Warren Gatland in January 2008.

[2] Williams was appointed Member of the Order of the British Empire (MBE) in the 2012 New Year Honours for services to rugby.