Jørgen Martinius Jensen (1878 – 1970) was a Norwegian military officer and sports official. He was born in Kristiania. He headed the Norges Landsforbund for Idrett from 1930 to 1932 and the Norwegian Equestrian Federation from 1936 to 1940. By profession he was a military officer, with the rank of colonel. He headed Opland dragonregiment, a dragoon regiment, from 1934 to 1943, and was as such involved in battles of the Norwegian Campaign, among others at Åsmarka and Tretten. After the war, from 1946 to 1956, he worked in the Norwegian Armed Forces department of war history.