Serie A's disciplinary tribunal said in a statement that Chiellini had been guilty of elbowing AS Roma's Miralem Pjanic in an off-the-ball incident during Juve's 1-0 win at the Stadio Olimpico on Sunday.
The tribunal used video evidence to make the decision as the incident was not seen by the referee.
Chiellini is a linchpin of the Italy side but will now have to wait to see if the incident will affect his World Cup chances, with Tuesday the deadline for provisional squads for June and July's tournament in Brazil.
Italy coach Cesare Prandelli has implemented a strict code of ethics since taking over in 2010 and has dropped a number of players for similar incidents in club games.
Roma striker Mattia Destro, banned for four matches for elbowing an opponent in April, was the latest victim when he missed out on two days of Italy fitness tests in April.
Prandelli warned at the time: "Anyone who messes around will stay at home, because it will mean that they can't handle the pressure of a World Cup."
Centre back Chiellini has been the mainstay of the Italy defence since Fabio Cannavaro quit international football after the 2010 World Cup and has won many admirers at home and abroad for his never-say-die attitude.
Italy are in World Cup Group D alongside England, Uruguay and Costa Rica.
(Reporting By Brian Homewood, editing by Mark Meadows)
