Tafeaga Junior Sa'u (born 18 April 1987) is a professional rugby league footballer who plays as a centre for the Keighley Cougars in RFL League 1. He has played for New Zealand and Samoa at international level. He previously played for the Newcastle Knights and the Melbourne Storm in the NRL, the Salford Red Devils in the Super League, and the Leigh Centurions in the Betfred Super League. He spent time in 2019 on loan from Salford at Wakefield Trinity in the Super League. Sa'u has also played rugby union for Old Glory DC in Major League Rugby (MLR) in the United States.