Career
Kristinn came through the youth ranks at, making his first appearance for the senior team in 2007, then at age 17. In 2015, Kristinn was voted the Úrvalsdeild player of the season by Icelandic national paper Morgunblaðið. On 1 January 2014, Kristinn moved to Swedish Allsvenskan side Brommapojkarna on loan from
On 26 November 2015, Kristinn moved to Norwegian Tippeligaen club 08.
At the age of 20 Kristinn had represented the Icelandic national team at all levels.