Jan Halvor Halvorsen (born 8 March 1963) is a former Norwegian football player and the current manager of Lyn.
In 2003, he joined Sogndal and helped the club to an 8th-place finish in his first season in charge of the Norwegian Premier League side.
In November 2005, he signed a contract with Notodden, bringing them up from the Norwegian Second Division up to Adeccoligaen, the second highest level in Norway.
During October 2010 it was reported that Halvorsen would be joining New York Red Bulls during the 2011 season to serve as the club's assistant manager under Hans Backe.
[3] Halvorsen signed a three-year contract with the Norwegian First Division side Bodø/Glimt ahead of the 2013 season, and replaced Cato Hansen as head coach and stated that the goal was to win promotion to Tippeligaen.