The 1945–46 Serie C was a special edition of Serie C, the third highest league in the Italian football league system. Best clubs of Northern Italy were admitted as special guests into the 1945–46 Serie B-C Alta Italia.
Northern Italy sides were divided in several rounds (gironi). The winners qualified to a tournament to determine the only team promoted to Serie B 1946-47. None of the teams relegated.
Mestrina promoted to 1946–47 Serie B.
All the winners of the rounds (gironi) were promoted to Serie B 1946-47; however, clubs participating as special guests could not be promoted. Later other teams were admitted to Serie B to create a southern round.