Locatelli was born in Toscolano-Maderno, near Brescia, Lombardy. At club level, he had a successful career, winning the Scudetto twice with Internazionale, in 1938 and 1940. He first played for Brescia between 1933 and 1936, aside from a brief loan to Atalanta, before transferring over to Inter, which was known as Ambrosiana Inter Milan at the time, where he remained until 1941. He ended his career with Juventus in 1949 following his transfer to the club in 1941, winning the Coppa Italia in 1942.