Italian FA (FIGC) president Maurizio Beretta has approved the proposal for a larger number of substitutes for Serie A matches, only three months after the idea was initially presented to the organisation by Napoli president Aurelio De Laurentiis.
Serie A teams will be forced to name a total of 23 players on a matchday, making their benches the largest in the highest tiers of world football.
The ruling will also be valid for Coppa Italia, Supercoppa Italiana and Primavera Championship fixtures effective immediately.
However, the decision has already been met with stiff opposition from Roma coach Zdenek Zeman, who believes an 18-man matchday squad to be sufficient.
"For me it does not change very much," he told reporters.
"It's unnecessary. In my experience 18 players was sufficient."
The Serie A season is due to start on Saturday, with the opening fixture involving Fiorentina and Udinese set to be the first game to experience the changes.