Career
Born in Garður, he started his career with his hometown club Víðir before joining Keflavík in 2001. After spending a year in the club"s reserve team, Guðjón made his league debut for Keflavík in the 2–2 draw with Grindavík on 8 July 2002. Over the following ten seasons, he went on to make more than 200 appearances for the side in all competitions and was involved in both the 2004 and 2006 Icelandic Cup finals, both of which ended in wins for Keflavík.
He also gained experience of playing in Europe as the team qualified for the and the Intertoto Cup.
On 22 March 2009, he made his international debut for Iceland in the 1–2 friendly defeat to the Faroe Islands.