Simunic, who was also given a £20,700 fine, will see his lengthy suspension all but end his international career.
A Fifa statement said: "The committee took note that the player, together with the crowd, shouted a Croatian salute that was used during World War II by the fascist "Ustase" movement.
"As a consequence, the committee agreed that this salute was discriminatory and offended the dignity of a group of persons concerning, race, religion or origin."
