Hans Fassnacht

Hans-Joachim Fassnacht (; born 28 November 1950) is a retired German swimmer. He competed at the 1968 and 1972 Summer Olympics in various freestyle and butterfly events and won a silver medal in the 4 × 200 m freestyle in 1972. In 1972, he also won a 1500 m freestyle semifinal, setting an Olympic record, but withdrew from the final.

During his career, Fassnacht set 41 German, 21 European and two world records, as well as five world best times. In 1969, while attending Long Beach State University under Coach Don Gambril, he broke the world record in the 400 m freestyle, and the following year broke another one in the 200 m butterfly. He was selected as West German Sportspersonality of the Year three consecutive times: in 1969, 1970 and 1971, beating Franz Beckenbauer. In 1992, he was inducted into the International Swimming Hall of Fame.