James William Slessor Marr (9 December 1902 – 30 April 1965) was a Scottish marine biologist and polar explorer.
Marr was born in Cushnie(Farm),Auchterless,Turriff, Aberdeenshire, Scotland. Son of Farmer John George Marr and Georgina Sutherland Slessor. He and Norman Mooney were two Boy Scouts who were selected by Sir Ernest Shackleton to join him on the Shackleton–Rowett Expedition in 1921, on board the vessel Quest. He later wrote the book Into The Frozen South (1923) about his experiences.
He took part in the British Australian and New Zealand Antarctic Research Expedition with Sir Douglas Mawson. He went on to become a marine biologist, taking part in the Discovery Investigations, specialising in Antarctic Krill.
Lieutenant Marr led Operation Tabarin during World War II. It was a small British Antarctica expedition launched from the United Kingdom in 1943 to the Antarctic to establish permanently occupied bases. Marr led the overwintering team at Port Lockroy in 1944.1936 - W. S. Bruce Medal - for his work in the southern ocean and more particularly for his monograph on the South Orkney Islands
7 October 1941 - Clasp to the Polar Medal (Bronze) - for good services between years 1925-1939, in the Royal Research Ships "Discovery II" and "William Scoresby": James William Sleesor Marr, Esq., M.A., B.Sc. (now Temporary Lieutenant, R.N.V.R.), H.M. Ships Discovery II and William Scoresby.
30 November 1954 - Polar Medal - For good services with the Falkland Islands Dependencies Survey in Antarctic expeditions: Temporary Lieutenant-Commander James William Slessor Marr, R.N.V.R., Base Leader, Port Lockroy, 1944.