Sitili Tupouniua (born 30 May 1997) is a Tonga international rugby league footballer who plays as a second-row forward for the Sydney Roosters in the NRL.
Tupouniua made his first grade debut for the Sydney Roosters in round 16 of the 2018 NRL season against the Melbourne Storm at Adelaide Oval.
Tupouniua scored his first try in the top grade against Canterbury-Bankstown in round 14 of the 2019 NRL season at the Sydney Cricket Ground.
Tupouniua featured for North Sydney, the Sydney Roosters feeder club in the 2019 Canterbury Cup NSW finals series. Tupouniua scored 2 tries in North Sydney's elimination final defeat by Newtown Jets at Leichhardt Oval.