William Cunningham was a New Zealand rugby union player who represented New Zealand—known as the All Blacks—between 1901 and 1908. Most notably he toured with the Original All Blacks on their 1905–06 tour of the British Isles, France and North America. They were the first New Zealand representative team to visit the British Isles, and of their 32 matches there Cunningham played in 23. He played mainly at lock, and was added to the touring party due to his strong scrummaging ability. He played in three Test matches during the trip: against Scotland, Ireland and France, but did not play in the loss to Wales due to injury, the All Blacks' only defeat on tour.

The Original All Blacks were the first New Zealand national rugby union team to tour outside Australasia. They toured the British Isles, France and the United States of America during 1905–1906. Their opening game, on 16 September 1905, was against Devon whom they defeated 55–4. They defeated every English side that they faced, including a 16–3 victory over English county champions Durham, and a 32–0 victory over Blackheath. They defeated Scotland, Ireland, and England with the closest of the three matches their 12–7 victory over Scotland. The team's only loss of the tour was a 3–0 defeat by Wales at Cardiff Arms Park. A try claimed by winger Bob Deans was not awarded by the referee and later became a subject of controversy. However, Wales were generally considered the better team with the All Blacks playing particularly poorly in the first half of the game. They managed narrow wins against four Welsh club teams and went on to play France in France's first-ever test match. They returned to New Zealand via North America where they played two matches against Canadian teams. Overall they played a total of thirty-five matches, which included five Tests, and only lost once—the defeat by Wales.