Soulan James Pownceby (née Soulan James Rikihana, born 4 May 1975 in Christchurch) is a New Zealand boxer who was described by TVNZ in 2004 as one of New Zealand's most exciting talents since David Tua. He is also notable for convictions for assault and manslaughter.

As an amateur, Pownceby was one of the New Zealand team's main hopes for a boxing medal in the 2006 Melbourne Commonwealth games but he was eliminated from the competition after losing 6–26 against his first opponent.

Pownceby had an impressive amateur record and won numerous New Zealand gold medals as a middle weight, light-heavy weight, and heavy weight.

Pownceby was also selected for the 2004 Athens Olympics and was the only boxer chosen to represent New Zealand at this event. Pownceby was eliminated from the competition after losing 19–33 against his first opponent.

Pownceby is a four time New Zealand National Amateur Champion, winning in 2001 (Middle), 2002 (Light Heavy), 2005 (Light Heavy) and 2006 (Heavy).

Pownceby defeated Joel Casey for the World Boxing Foundation light-heavyweight title on 17 June 2010. Pownceby, who was ranked 9th in the July 2010 WBO light heavyweight rankings, was in superb form and won the fight over 12 rounds.

Pownceby has also held the WBO Asia Pacific light-heavyweight title after defeating Togasilamai Letoa in a 12-round fight.

Pownceby is ranked fifth in New Zealand's pound for pound record.