Admiral Sir William George Tennant was a British naval officer. He was lauded for overseeing the successful evacuation of Dunkirk in 1940. Tennant subsequently served as captain of the battlecruiser HMS Repulse, when she searched for German capital ships in the Atlantic. He remained in this capacity when the Repulse was sunk by the Japanese along with HMS Prince of Wales in the South China Sea on 10 December 1941, three days after the attack on Pearl Harbor. He later aided in the setup of the Mulberry harbours and the Pluto pipelines, a crucial part of the success of Operation Overlord. He died in 1963.

The Dunkirk evacuation, codenamed Operation Dynamo and also known as the Miracle of Dunkirk, or just Dunkirk, was the evacuation of more than 338,000 Allied soldiers during the Second World War from the beaches and harbour of Dunkirk, in the north of France, between 26 May and 4 June 1940. The operation commenced after large numbers of Belgian, British, and French troops were cut off and surrounded by German troops during the six-week Battle of France.