Claus Helberg (31 January 1919 – 6 March 2003) was a Norwegian resistance fighter and mountain guide.[1] He was a member of Company Linge, a resistance commando unit that was best known for carrying out Norwegian heavy water sabotage during World War II. After the war, he worked for the Norwegian Mountain Touring Association until his retirement in 1982.[1] While volunteering with the Association after his retirement, he helped guide several members of the Scandinavian royalty. According to The New York Times, "[he was] the favorite mountain guide of Scandinavian royalty..."[1] These clients included Queen Sonja and Margrethe II of Denmark.