John Halvorsen (born 17 August 1966) is a retired Norwegian long-distance runner who specialized in 10,000 metres and cross-country running.
In 10,000 m he finished sixteenth at the 1988 Summer Olympics, twelfth at the 1990 European Championships and nineteenth at the 1992 Summer Olympics.
At the 1987 World Championships he competed in both 10,000 m and 5000 m without reaching the finals.
He also attended University of Ottawa and is also a record 4 times Canadian University (CIAU) Cross Country Champion and a 5 times all Canadian as well as two times Canadian Cross Country Champion and won several Canadian 10K Road Championships.
He was very successful on the US Road Racing Circuit and was the 1989 Runners World Road Racer of the Year and won several of the major US Road Races including the Lilac Bloomsday 12 km, Gaspatilla 15 km, Red Lobster 10 km, Boston Milk Run and holds the 14th fastest all-time 12 km Road Race Performance He is the past Race Director for the Ottawa Race Weekend featuring the Ottawa Marathon and the Ottawa 10K for which he held the course record for 20 years (28:12 set in 1988)[1] He was a founding organizer of the Canada Army Run also held in Ottawa.