Halfdan Olaus Christophersen (13 December 1902 – 27 May 1980) was a Norwegian historian, literature researcher and non-fiction writer.
During the occupation of Norway by Nazi Germany he was a central member of the Norwegian resistance movement.
After World War II, he served as director of the Department of Information Science and Media Studies at the University of Bergen (1946-1954).
Among his other works are biographies of Marcus Jacob Monrad, Eilert Sundt and Niels Treschow.
He wrote several books on the history of travelling and tourism, and World War II memoirs Fra nød til seir.