Thorleif Oscar Karlsen (17 December 1909 – 31 January 2010) was a Norwegian police inspector and politician, who also became known through the radio program Trafikk og musikk. He was born in Stavanger, to which his parents had moved in the same year. He was hired as a police officer in 1930. He worked in Stavanger from 1930 to 1932, for Statspolitiet in Oslo from 1932 to 1937 and then in Stavanger again from 1938. During the occupation of Norway by Nazi Germany he was arrested in February 1941 for "anti-German propaganda". He was imprisoned at Møllergata 19 from 26 February to 22 March, then at Ånebyleiren concentration camp until 16 April. He was freed, but was later arrested again during a crackdown on the police (Norwegian: politiaksjonen), and was then imprisoned at Grini concentration