Julius Lenhart (November 27, 1875 in Vienna – November 10, 1962 in Vienna) was an Austrian gymnast who competed in the 1904 Summer Olympics. He won two gold medals and one silver medal, making him the most successful Austrian competitor ever at the Summer Olympic Games. Because athletes did not compete for their nations at early Olympic Games as they do now, the International Olympic Committee credit's Lenharts medals to the United States instead of Austria, as he was representing his Philadelphia-based club.