The Serie B 1946–47 championship was organized by the Lega Calcio with geographical criteria: for this reason the three groups have different numbers of participants.
However, war damages and political choices imposed to divide the old Serie B between Northern and Southern Italy.
Consequently, 20 Northern clubs from the previous Serie B-C and 14 selected teams from Southern Italy were added.
To reduce the fixtures to 34 matchdays the following season, four teams per group and an additional club from Northern Italy had to be relegated.
Biellese qualified for the Northern Italy relegation play-off while Vogherese remained in Serie B. Pisa was saved while Anconitana qualified for the Northern Italy relegation play-off.