William 'Billy' Cleaver (15 September 1921 – 29 September 2003) was a Welsh international Rugby Union fly-half who played club rugby for Cardiff. He won 14 caps for Wales and was selected to play for the British Lions on the 1950 tour of Australia and New Zealand. He was in the Welsh team that won the 1950 Grand Slam.Born in 1921 in Treorchy, Rhondda, Cleaver was an exciting attacking player with a shrewd change of pace.