Knut Ingolf Løfsnes (22 December 1918 – 5 January 1996) was a Norwegian resistance member, politician and lawyer. He was a central leader of the clandestine organization XU during the occupation of Norway by Nazi Germany, leading the mid-Norway XU department from the Norwegian legation in Stockholm from 1942 to 1945. He was the first chairman of the Socialist People's Party, from 1961 to 1969.