Fifa president Sepp Blatter and Uefa boss Michel Platini have been suspended for eight years from all football-related activities following an ethics investigation.
They were found guilty of breaches surrounding a £1.3m ($2m) "disloyal payment" made to Platini in 2011.
Both men denied any wrongdoing.
The bans come into force immediately.
Fifa boss since 1998, Blatter, 79, had already announced he was quitting ahead of February's presidential election.
Platini, 60, was tipped as a future leader of football's world governing body and had hoped to succeed Blatter.
A three-time European Footballer of the Year and former captain of France, he had been in charge of Uefa - European football's governing body - since 2007.
Both men have also been fined.
Blatter must pay £33,700 (£40,000), while Platini £54,000 ($80,000),
Why are they banned?
Blatter and Platini were found guilty of ethics code breaches surrounding a £1.3m ($2m) "disloyal payment" made to the Frenchman in 2011.
Both claimed the payment was honouring an agreement made in 1998 for work carried out between 1998 and 2002 when Platini worked as a technical adviser for Blatter.
The payment was not part of Platini's written contract but the pair insisted it was a verbal agreement, which is legal under Swiss law.
German judge Hans-Joachim Eckert, the chairman of Fifa's adjudicatory chamber, held disciplinary hearings for the pair last week.
Charges included conflict of interest, false accounting and non co-operation, with investigators submitting a file of more than 50 pages.
Statement - key points
"The proceedings against Mr Blatter primarily related to a payment of CHF 2,000,000 transferred in February 2011 from Fifa to Mr Platini.
"Mr Blatter, in his position as president of Fifa, authorised the payment to Mr Platini which had no legal basis in the written agreement signed between both officials on 25 August 1999.
"Neither in his written statement nor in his personal hearing was Mr Blatter able to demonstrate another legal basis for this payment.
"His assertion of an oral agreement was determined as not convincing and was rejected by the chamber...
"Mr Platini's assertion of an oral agreement was determined as not convincing and was rejected by the chamber."
Is this the end for both men?
Platini boycotted his hearing in Zurich on Friday in protest, claiming a decision already appeared to have been made.
His lawyers attended, but it looks as though the Frenchman is preparing to take the matter to the Court of Arbitration for Sport.
As for Blatter, he is planning to hold a news conference at 1000 GMT, when we will find out what he plans to do.
He has already announced he would not be seeking a fifth term as Fifa president but is unlikely to accept the ruling of the ethics investigators.
Whatever happens, they will find it hard to recover from the damage to their reputations.