Florence May Chadwick (November 9, 1918 – March 15, 1995) was an American swimmer. She was known for long-distance swimming. At age 10 she was the first child to swim the Catalina Channel. Chadwick was the first woman to swim the English Channel in both directions. She set a time record each time. She was the first woman to swim the Straits of Gibraltar, the Bosporus (one way), and the Dardanelles (round trip).