Øistein Stømnæs (28 June 1914 - 21 July 1980) was the head of XU, the main Norwegian intelligence organization from 1943 to 1945. Strømnæs was born in Sarpsborg in Østfold county, Norway. He studied biology at the University of Oslo and was working of his Master's degree student in botany when Norway was attacked in 1940. To support his studies he also had a part-time job as a police constable, this proved very valuable when he got involved in intelligence.