SS Athenia was a steam turbine transatlantic passenger liner built in Glasgow, Scotland, in 1923 for the Anchor-Donaldson Line, which later became the Donaldson Atlantic Line. She worked between the United Kingdom and the east coast of Canada until 3 September 1939, when a torpedo from the German submarine U-30 sank her in the Western Approaches.
Athenia was the first British ship to be sunk by Germany during World War II, and the incident accounted for the Donaldson Line's greatest single loss of life at sea, with 117 civilian passengers and crew killed. The sinking was condemned as a war crime. Among those dead were 28 US citizens, causing Germany to fear that the US might join the war on the side of the British Empire and France. Wartime German authorities denied that one of their vessels had sunk the ship. An admission of responsibility did not come from Germany until 1946.