Florence May Chadwick (November 9, 1918 – March 15, 1995) was an American swimmer known for long-distance open water swimming. She was the first woman to swim the English Channel in both directions, setting a time record each time. She was also the first woman to swim the Catalina Channel, the Straits of Gibraltar, the Bosporus (one way), and the Dardanelles (round trip).