1920–21 Prima Categoria

The preliminary regional phase became the bulk of the tournament, with even sixteen matchdays and regular regional football champions, while the following national phase was reduced to a spring tournament of eight matchdays.

The main tournament was completely divided in five independent sections, and each region had its own football champions.

They variously chose to promote, re-elect, or invite clubs to fill the spots they had been granted to.

Rivarolese was demoted by the Federazione Italiana Giuoco Calcio after incidents caused by its supporters during the match Rivarolese-Savona (0–2).

A tie-breaker was due, but both Legnano and Torino decided to retire from the championship and to resign from the FIGC.