Schiavio spent his entire career with Bologna, joining them in 1922 at the age of 16. Although he made only six appearances in that first season, he soon established himself as an important member of the first time. In just his third season, Bologna won their first league title, with Schiavio providing 16 goals in 27 matches. They repeated as champions in 1929, getting 30 goals from Schiavio in just 26 games.
He made his national team debut for Italy in 1925 and was the team's top scorer in their bronze-medal winning 1928 Olympic campaign with four goals.
Italy did not participate in the 1930 World Cup, but hosted the second tournament in 1934. There, Schiavio scored a hat-trick in their opening match against the United States, which Italy won 7-1. He did not score again in that tournament until the final, when his 95th-minute strike put Italy ahead of Czechoslovakia 2-1 and captured the trophy. It was the last of his 15 international goals.
He retired in 1938, having scored a club-record 242 goals for Bologna.