Ivo Stefanoni took up rowing in 1951 and two years later won his first of 15 Italian national titles in the sport through 1972. In 1956 Stefanoni, alongside Alberto Winkler, Romano Sgheiz, Angelo Vanzin, and Franco Trincavelli, took bronze in the coxed four at the European Championships, before going on to win gold in that event at the Melbourne Olympics. Four years later, Stefanoni, with Sgheiz, Trincavelli, Fulvio Balatti, and Giovanni Zucchi, captured bronze at the Rome Games. In between the Olympics, Stefanoni won gold in the eights at the 1957 and 1958 European Championships, and captured a final European title in that event in 1961. He competed in the eights at the 1964 Tokyo Olympics and finished sixth. In 2015 he received the Collare d’Oro for Sporting Merit rom the Italian National Olympic Committee (CONI).