Arnar Darri Pétursson (born 16 March 1991) is an Icelandic professional footballer who plays as a goalkeeper for Stjarnan.
He started his career with Stjarnan, and joined Oslo-based club Lyn in March 2008.
At the time Arnar moved to Lyn they had among others Indridi Sigurdsson, Theodor Elmar Bjarnason and more quality players.
He made his Norwegian Premier League debut for Lyn on 3 August 2009 against SK Brann.
On 1 July 2010, Arnar signed for Danish Superliga club SønderjyskE, which is located near the German border, to compete with their existing number one goalkeeper Nathan Coe.