A hardline statement was issued by football's world governing body on Friday, despite Barcelona having won a court ruling in 2008 against being obliged to release Lionel Messi for the Beijing tournament.
It means that FIFA will not leave a decision to clubs; for example for Arsenal to decide whether Jack Wilshere and Aaron Ramsey can play for the British team.
A FIFA statement read: "The executive decided that the release of the U-23 players by clubs for Olympic football tournaments will be compulsory."
The Football Association have assured clubs that Team GB coach Stuart Pearce will not select any player for the British men's team if they have been in the England squad for Euro 2012.
Each men's squad is made up of Under-23 players plus three over-age players.
ELSEWHERE ....
Arsenal boss Arsene Wenger feels the Football Association must sort out who will be England manager sooner rather than later.
Former Manchester United defender Gary Neville believes time is running out ahead of Euro 2012 to name Fabio Capello's replacement, while ex-England boss Terry Venables, who backed Harry Redknapp for the job, criticised the FA for not acting swiftly enough.
The FA have made it clear they want to wait until early May in order to avoid destabilising any club, and also because if the next manager is currently in work, he would not leave his club until the end of the season.
Frenchman Wenger, 62, has himself been approached for the England job in the past, and accepts the FA are in a difficult position, but one which must be resolved quickly.
"I don't know their plan completely, I think they have been taken by surprise a bit with Capello going," said Wenger.
"They are now in a difficult situation and the sooner they sort it out, the better it is, but it is not easy for the federation [FA] at the moment because they do not want to interfere with what is going on in the Premier League. You can understand that."