Matt Mostyn is a retired Irish-Australian rugby player. He earned six caps playing as a wing for the Ireland national rugby union team, including four at the 1999 Rugby World Cup, being eligible through a grandparent from County Tyrone. He played club rugby with the New South Wales Waratahs in Australia, with Bordeaux in France, Newport in Wales and Ireland, finishing his career at Connacht and Galwegians in 2008.