The Frenchman appeared to strike the Bianconeri center back in the back of the head as the two competed for a corner during the second half of Sunday's game in Turin.
The incident occurred six minutes into the second half of Sunday's Serie A meeting in Turin, with the France international appearing to strike the Bianconeri center back in the back of the head after they had both attempted to connect with an Andrea Pirlo corner.
An enraged Chiellini later called for Mexes to be "heavily punished," and the league has now confirmed that the Rossoneri ace has been suspended for four games.
The ruling body explained that one game related to the 31-year-old's later dismissal for a second bookable offense, with the other three games the result of the player having been found guilty of violent conduct courtesy of televisual evidence supplied by broadcaster Sky Sport Italia.
Mexes' ban is a major blow for a Rossoneri side that has already conceded 13 goals in seven games so far this season.