Sonny William 'Sonny Bill' Williams (born 3 August 1985) is a New Zealand rugby union and rugby league footballer, heavyweight boxer, and volleyball player. He is only the second person to represent New Zealand in rugby union after first playing for the country in rugby league, and is one of only twenty players to have won two rugby union World Cups.
In rugby league, Williams has played seven seasons in two spells in the National Rugby League (NRL), with the Canterbury Bulldogs and Sydney Roosters. He has won 12 caps for New Zealand (the Kiwis) and won the RLIF Awards for Rookie of the Year in 2004 and International Player of the Year in 2013.
He first moved to rugby union in 2010 and has since had spells playing for Toulon in France, Canterbury, Counties Manukau, the Crusaders, Chiefs and Blues in New Zealand and Panasonic Wild Knights in Japan. He has won 46 caps for New Zealand (the All Blacks), and was part of the teams that won the 2011 and 2015 Rugby World Cups. He has also played rugby sevens for New Zealand, competing in the 2015–16 World Rugby Sevens Series and the 2016 Olympics.