SS John Witherspoon was a Liberty ship built in the United States during World War II. She was named after John Witherspoon, a Scottish-American Presbyterian minister and a Founding Father of the United States. Politically active, Witherspoon was a delegate from New Jersey to the Second Continental Congress and a signatory to the United States Declaration of Independence. Later, he signed the Articles of Confederation and supported ratification of the Constitution. In 1789 he was convening moderator of the First General Assembly of the Presbyterian Church in the United States of America.

John Witherspoon was laid down on 10 December 1941, under a Maritime Commission (MARCOM) contract, MCE hull 31, by the Bethlehem-Fairfield Shipyard, Baltimore, Maryland; sponsored by Miss Grace Rose Culleton, the daughter of J.C. Dulleton, the resident MARCOM plant auditor, and was launched on 4 March 1942.

She was allocated to Seas Shipping Co.Inc., on 23 April 1942.

John Witherspoon had set out from Baltimore, on her maiden voyage, in June 1942. She sailed from Hvalfjordur, Iceland, on the afternoon of 27 June 1942, with 8,575 LT (8,713 t) of ammunition and tanks aboard, for Arkhangelsk, in Convoy PQ-17. At 16:38, on the afternoon of 6 July 1942, John Witherspoon was struck by a torpedo fired from the German submarine U-255, at 72°05′N 48°30′E / 72.083°N 48.500°E / 72.083; 48.500. The torpedo struck her starboard side between holds #4 and #5. A minute later another torpedo struck beneath the bridge. All eight officers, 31 crewmen, and 11 Armed guards abandoned ship at this time, with one crewman falling overboard and drowning. At 16:55, another two torpedoes struck the port side amidships, this caused her to brake in two and sink within minutes. U-255 approached the lifeboats to question the captain, John Stewart Clark, about her cargo, afterwards offering food and water to the survivors and directions to the nearest land.

The merchant ship El Capitan, picked up 19 of the survivors on 8 July, with HMS La Malouine (K46) picking up the rest of survivors on 9 July. With El Capitan being attacked on 9 July, the survivors were once again forced to abandon ship, this time being rescued by HMS Lord Austin (FY220).