The 59-year old has since been replaced by Claudio Ranieri as the Greece national coach after his contract expired at the end of the World Cup.
FIFA said in a statement that Santos, who was sent from the dugout at the end of extra time in the last-16 tie on June 29, had been guilty of “several acts of unsporting conduct towards the match officials”.
FIFA also confirmed that Santos must serve the ban in official competitive matches played by the next national team he coaches. The sanction is likely to end the Portuguese coach’s top-level international career.
Santos has been given the right to appeal.