Siv Jensen (born 1 June 1969 in Oslo) is the chairwoman of the Progress Party, a libertarian conservative party in Norway. She was appointed party chairwoman on 6 May 2006, after a long period of being next in leadership, after Carl I. Hagen, party's chairman for 28 years, resigned in 2006. In September 2006 a political biography on Siv Jensen was released written by chief editor of the magazine Ny Tid, Martine Aurdal.
Jensen is unwed and has no children.
She has maintained Norway's neutrality policies ever since her leading the party to victory in the elections of 2007.