John Elliot Hart (April 4, 1824 – June 11, 1863) was an officer in the Union Navy during the American Civil War. He died in June 1863 on board his ship USS Albatross while taking part in the Union attempt to blockade the Mississippi River. He is best known for the unusual circumstances of his burial in Louisiana, which the town of St. Francisville, Louisiana, commemorates every year in a three-day festival called "The Day the War Stopped".