William Helu (born 19 April 1986) is a Tongan rugby union player. His usual position is on the wing or at centre. He is part of the Tonga national rugby union team and was part of the 2011 Rugby World Cup. Helu was part of the Tongan squad that defeated France in the pool games at the 2011 Rugby World Cup in New Zealand. He signed with Bristol on a two-year deal but chose to leave the club for personal reasons after the 2011–2012 season. Helu signed a two-year deal with Edinburgh in 2015.