Hannes Thor Halldorsson is an Icelandic footballer who plays as a goalkeeper for Randers FC and the Iceland national team..

Hannes has played club football in Iceland for Leiknir, Afturelding, Stjarnan, Fram and KR. On 28 March 2012, Hannes joined Norwegian club SK Brann on a short-term loan, as a cover for injured goalkeeper Piotr Leciejewski.In December 2013 Hannes joined Norwegian club Sandnes Ulf, having trained with the club in October 2013 as preparation for Iceland's World Cup playoff game against Croatia.On 6 July 2015 Dutch Eredivisie club NEC announced they had signed Hannes on a 2-year contract.

He made his international debut for Iceland in 2011, keeping a clean sheet in a Euro 2012 qualifier against Cyprus. After appearing in all twelve 2014 World Cup qualifiers for Iceland, Hannes is considered the main goalkeeper of the national team. He was selected for EURO 2016.