Arve Johannes Lønnum (2 October 1911 – 18 December 1988) was a Norwegian professor of medicine and politician for the Progress Party. He was born in Egge, Nord-Trøndelag. He took the cand.med. degree in 1945 and the dr.med. degree in 1966. He was a chief physician at the Akershus University Hospital and professor in neurology at the University of Oslo. He was decorated with the Royal Norwegian Order of St. Olav. He died in December 1988.