Andreolo played for Nacional in Uruguay before joining Serie A team Bologna F.C. 1909 ahead of the 1935–36 season and helping them win the league title (Scudetto). He would remain in Bologna until 1943, winning the Scudetto three more times, in 1936–37, 1938–39 and 1940–41.
Following his success with Bologna, he was called up to the Italian national team by Vittorio Pozzo and debuted on 17 May 1936 against Austria. He soon became a regular in the team, playing his crucial role of connection between defence and attack. He helped win the 1938 FIFA World Cup in France, and played his last match for the national team on 19 April 1942, having earned 26 caps and 1 goal.