Suaia Matagi (born 23 March 1988), also known by the nickname of "Sui", is a professional rugby league footballer who plays as a prop forward for Doncaster R.L.F.C.

He previously played for the New Zealand Warriors, the Sydney Roosters, the Penrith Panthers and the Parramatta Eels in the NRL, and the Huddersfield Giants and the Castleford Tigers in the Super League.

[5] He attended Kelston Boys' High School[6] before dropping out at age 14, having become involved in gang violence, and heavy alcohol abuse.

He played for the Te Atatu Roosters, and later the Mount Albert Lions in the Auckland Rugby League competition.

[8][10] He was named man of the match in Auckland's 44-34 victory over the South Island Scorpions in the National Competition's 2011 Grand Final.

[11] Matagi made his debut for the Auckland Vulcans, the New Zealand Warriors' feeder team, in the New South Wales Cup on 3 April 2010.

In May 2015, Matagi requested, and was granted, a release from his contract with the Warriors in order to sign with the Sydney Roosters effective immediately.

Matagi played a total of nine games for Parramatta in the 2018 NRL season as the club endured a horrid campaign finishing last on the table.

Matagi said of the move "I am extremely excited to take my football to the next level under the leadership of coach Simon Woolford and I'm also looking forward to the challenge of playing in the English Super League, joining a proud club like the Huddersfield Giants is a privilege and I will represent our fans to the best of my ability".

[28] On 10 October 2021, it was announced that Matagi had signed a deal to remain at Castleford on a permanent basis, joining the Tigers on a two-year contract.

[34] Matagi made his international debut for Samoa at the 2013 World Cup, playing in all four of their matches, scoring tries against New Zealand and Papua New Guinea.