[9] Jón Arnar was hired as the head coach of Haukar in November 1998, replacing recently fired Einar Einarsson.

After a disappointing start of the 2005–2006 season, the board of Breiðablik fired Jón Arnar in December 2005.

[13] Jón Arnar was hired as the head coach of ÍR in 2006 and led them to victory in the Icelandic Cup in his first season.

[16] He stepped down as the head coach of the club on 1 February 2013 after a disappointing tenure with the team in last place.

[17] Jón Arnar is the son of Ingvar Jónsson, a former player and coach for Haukar.