Henri Julius Reverony Saint Cyr (15 March 1902 – 27 July 1979) was a Swedish officer and equestrian. He competed at five consecutive Olympics from 1936 to 1960 and won two gold medals in 1952 and two in 1956, all in individual and team dressage. At his last Olympics in 1960 he finished fourth in the individual dressage.
Saint Cyr was the national champion in eventing in 1935, 1937, and 1939 and won a world title in the individual dressage in 1953. He took the Olympic Oath at the 1956 Games in Stockholm.