Harold Thompson Mann (December 1, 1942 – April 4, 2019) was an American swimmer. He competed at the 1964 Summer Olympics in Tokyo. At that Olympic Games, he won a gold medal for swimming the lead-off backstroke leg for the winning U.S. team in the 4 x 100-meter medley relay. He and his relay teammates Bill Craig (breaststroke), Fred Schmidt (butterfly) and Steve Clark set a new world record of 3:58.4. Mann also set an individual world record in the 100-meter backstroke swimming his leg (59.6 seconds). He was born in Norfolk, Virginia.