Saia Fainga'a (born 2 February 1987) is an Australian professional rugby union footballer who plays Super Rugby for the Queensland Reds.
Saia Fainga'a was born in Queanbeyan, New South Wales, and started playing rugby union at the age of 11 or 12 at the Queanbeyan club. He was a member of the Brumbies Academy from the age of 14 and attended St Edmund's College, Canberra, where he was selected for the Australian Schools team in 2003 and 2004.
Saia's twin brother Anthony, and younger brother's Vili and Colby are also professional rugby union players. The Fainga'a's are of Tongan and Aboriginal descent.