Iain Fullarton (born 25 April 1976) is a Scottish rugby union player. While at Merchiston Castle School he appeared for the Scottish schools side. After leaving Merchiston, Fullarton turned professional with Edinburgh Reivers and has since played for Sale Sharks. He signed for Saracens in 2004. In 2008 he left Saracens. He signed a two-year deal in June 2008 to play for London Scottish.
Fullarton represented Scotland at under 21, under 19 and under 18 levels and made 15 appearances for the Scotland A side. He made his full Scotland debut in their tour of New Zealand in 2000, replacing Scott Murray in the first Test against New Zealand, and was subsequently selected in the starting line up for the second test. He won his third cap, again as a replacement for Scott Murray in the November 2001 Test, also against New Zealand. He won his fifth cap for Scotland when he came on as a substitute in the 2003 Rugby World Cup countdown Test against Ireland in 2003. Earlier that summer he toured South Africa with Scotland but did not play in either Test match. As of 21 April 2006 he has won eight international caps.