William John Mumm OBE JP (26 March 1922 – 11 December 1993) was a New Zealand rugby union player.

He was selected as one of the 5 players of the year for the 1945 season in the Rugby Almananac of New Zealand.

[2] He was a member of the New Zealand national side, the All Blacks, in 1949, playing one test match against Australia.

[3] He later served as chairman of the Buller County Council[3] and was appointed an Officer of the Order of the British Empire in the 1990 Queen's Birthday Honours, for services to local government.

This biographical article relating to New Zealand rugby union, about a person born in the 1920s, is a stub.