Uruguay and Liverpool striker Luis Suarez has been suspended from all football-related activity for four months and for nine international matches, for biting Italy defender Giorgio Chiellini.
The ban rules him out of the remainder of Uruguay's matches at this World Cup, but even if they should win the tournament, he will only miss four matches.
The incident occurred during Tuesday's 2014 World Cup Group D game, which Uruguay won to qualify for the last 16. Uruguay have three days to appeal against the decision, and Suarez has also been fined 100,000 Swiss francs (£65,680).
The ban is the biggest in World Cup history, beating the eight games given to Italy's Mauro Tassotti for elbowing Spain's Luis Enrique in 1994.
"Such behaviour cannot be tolerated on any football pitch and, in particular, not at a Fifa World Cup when the eyes of millions of people are on the stars on the field," Claudio Sulser, chairman of the Fifa disciplinary committee, said in a statement.
Suarez has now been found guilty of biting three opponents in his career. He was banned for 10 games for biting Chelsea's Branislav Ivanovic during a Premier League match in 2013 and was also suspended for seven games for biting PSV Eindhoven's Otman Bakkal in 2010.
The ban will have significant repercussions for his club Liverpool, with him set to miss the first nine games of the Premier League season, their Third Round Capital One Cup tie, as well as their first three Champions League Group Stage matches.
The ban will intensify speculation that he will leave Liverpool this summer, with Spanish giants Barcelona and Real Madrid reportedly ready to swoop with big money offers.