Career
Ögmundur made his senior debut for Fram on 12 June 2006, a week before his 17th birthday, in the 2006 season of the Icelandic second tier, starting against Haukar in the absence of Gunnar Sigurðsson. His next match came in the 2009 Icelandic Premier League season in the last match of the season, entering as a half-time substitute for Hannes Þór Halldórsson and keeping a clean sheet in the second half as Fram lost 1-0 to Þróttur R. at home. He remained a reserve goalkeeper to Hannes Þór Halldórsson in the 2010 season.
When Hannes transferred to KR after the 2010 season Ögmundur became the main goalkeeper for Fram.
He has played every league game since the start of the 2011 season. On 30 December 2011, Ögmundur was given the honorary title "Fram Sportsman of the Year", the first football player to hold that title.
After the 2013 season he went on a trial to Norwegian club Sandnes Ulf and Scottish club Motherwell. His trial at Motherwell went well, although they were not looking to buy a goalkeeper at that time.
On 16 July 2014, half-way through the Icelandic 2014 season, Ögmundur joined Danish club Randers, signing a one-year contract.
On 2 June 2015 Ögmundur signed a 3-year deal with Hammarby IF, eventually making 15 appearances in the 2015 Allsvenskan for his new side. Ögmundur made his first international appearance on 4 June 2014 in a match against Estonia, when he came on as a substitute for Gunnleifur Gunnleifsson at half-time. In that second half, he kept a clean sheet, to maintain Iceland"s 1–0 lead.
On 13th October 2015, Kristinsson made his competitive debut in a Union of European Football Associations Euro 2016 qualifying game against Turkey, with Iceland already being qualified for the championship.
Despite putting on a solid effort, Iceland went on to lose with the score of 1-0 after a free kick goal by Selçuk İnan in the 89:th minute.