William Martin Kelly (1892–1975), born in Westport, New Zealand was a rugby league football identity who enjoyed success in New Zealand and Australia as both a player and coach in the first half of the 20th century. He played for Wellington, the Balmain Tigers, New South Wales and for both the New Zealand and Australian national sides. He also had a long coaching career with five different clubs in the NSWRFL in the 1920s, 1930s and 1940s, and with New Zealand in 1932.

The Balmain Tigers are a rugby league club based in the inner-western Sydney suburb of Balmain. They were a founding member of the New South Wales Rugby League and one of the most successful in the history of the premiership, with eleven titles. In 1999 they formed a joint venture club with the Western Suburbs Magpies club to form the Wests Tigers for competition in the National Rugby League (NRL). They no longer field any senior teams in the lower divisions. At the time of the joint venture only South Sydney Rabbitohs and the St George Dragons had won more titles than the Tigers.