Fifa president Sepp Blatter and Uefa boss Michel Platini have been suspended for eight years from all football-related activities following an ethics investigation.
The bans come into force immediately.
At 79, Blatter's suspension effectively ends his long career as a football administrator.
Fifa boss since 1998, the Swiss had already announced his intention to stand down before 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 ( $NZ59,000), while Platini £54,000 ($NZ118,640).
Blatter and Platini were found guilty of ethics code breaches surrounding a £1.3m ($NZ2.9m) "disloyal payment" made to the Frenchman in 2011.
Both men denied any wrongdoing and 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.
Fifa ethics statement - key points
- The payment made in February 2011 had "no legal basis" in the contract signed by both men when Platini started working for Blatter on 25 August, 1999.
- Both men's explanation that there was an "oral agreement" over the payment was rejected as "not convincing".
- Blatter's actions did not show "commitment to an ethical attitude", and both men were found to be in "a conflict of interest".
- Platini also failed to act with "complete credibility and integrity" and showed "unawareness of the importance of his duties".
- The committee said there was "not sufficient evidence" to establish the payment was a bribe, but both men demonstrated an "abusive execution" of their positions.
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.
"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," Judge Eckert said.
"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."
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.
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.
Unshaven and sporting a plaster over his right cheek, Blatter was in defiant mood at a news conference he had called in advance of the punishments being made public.
"I will fight," he said. "I will fight for me and for Fifa."
He said he was "really sorry" that he is still "a punching ball" and that he has become tainted in the eyes of humanity.
He added that he thought he had convinced the Fifa ethics tribunal that the payment from Fifa to Platini was legitimate.
He plans to appeal, first to Fifa, then Cas. He may also take legal action under Swiss law if needed.
"The decision is no surprise to me," Platini said in a statement. "The procedure initiated against me by Fifa's ethics committee is a pure masquerade.
"It has been rigged to tarnish my name by bodies I know well and who for me are bereft of all credibility or legitimacy."
In the meantime, Uefa has issued a statement, revealing it is "extremely disappointed" with the decision.
It added: "Once again, Uefa supports Michel Platini's right to a due process and the opportunity to clear his name."
Reform group ChangeFIFA said the action would hopefully see the start of a real turnaround for the organization.
Co-director David Larkin told Morning Report the action was the result of increasing pressure from US law enforcement to clean up the game.
"This is an organisation that has zero credibility, at this point the only way to change this organisation is with a cultural change, and the only way for that to happen is for a complete replacement of the people at the top."
Mr Larkin said he was hopeful the appeals process follow would shed some light on the situation, as there were still many things which have not been explained.
What now for Fifa?
World football's governing body has been in turmoil for several months now, following numerous allegations of corruption.
Seven Fifa officials were arrested at a Zurich hotel at the end of May.
And US authorities have charged 39 football officials and sports business executives over more than ($NZ296m) in bribes for football television and marketing deals.
Swiss prosecutors are also investigating Fifa's management as well as the award of the 2018 and 2022 World Cups to Russia and Qatar.
There is also pressure from governments and the International Olympic Committee for Fifa to push through major reforms aiming at making governance more transparent and accountable.
Fifa's presidential election is due to take place on 26 February.
Voting will take place by secret ballot, with all Fifa's 209 member states having a vote each.