RRS Discovery II was a British Royal Research Ship which, during her operational lifetime of about 30 years, carried out considerable hydrographical and marine biological survey work in Antarctic waters and the Southern Ocean in the course of the Discovery Investigations research program.

Built in Port Glasgow, launched in 1928 and completed in 1929, she was the first purpose-built oceanographic research vessel[2] and was named after Robert Falcon Scott's 1901 ship, RRS Discovery.

[3] The ship's maiden voyage took place from December 1929 to May 1931 and consisted of a hydrographic survey of the South Sandwich Islands.

Similar voyages took place from 1934 to 1939 during which she supplied the British Graham Land expedition.

In December 1935 and January 1936, the ship was involved in a successful rescue of American polar explorer and aviator Lincoln Ellsworth and his English copilot Herbert Hollick-Kenyon after their aircraft ditched in the Ross Sea near the Bay of Whales.