Gunnar Þor Gunnarsson (born 4 October 1985) is an Icelandic football player who currently represents KR in Pepsi deildin. He left Hammarby IF on 1 November 2007 to sign a three-year contract with IFK Norrkoping.
He joined Hammarby IF before the 2006 season, leaving Icelandic club Fram. He is a defender who plays most commonly at left back.