"This is fantastic news for Wales, Cardiff and the Millennium Stadium and it will be an honour to host the 125th anniversary FA Cup final in what is the 125th anniversary season of the Welsh Rugby Union," said Millennium Stadium Chief Executive Paul Sergeant.
"We had made the Stadium available to the Football Association as cover for the new Wembley some time ago and we are delighted to be able to entertain them and their guests for one last time in May. That said, we wish Wembley all the best with the final phase of its development.
"The Millennium Stadium became the ninth venue to host the FA Cup final in 2001 and there is little doubt that our connection with such a world renowned event has greatly enhanced our reputation. The six finals we have hosted will live long in the history of not only the Millennium Stadium, but also of Welsh sport."
The Football League has also announced that the 2005/06 Coca-Cola Football League Play-Off Finals will be held at the Millennium Stadium on May 21/27 and 28.
Football League Head of Communications John Nagle said: "The Football League has exercised an option, negotiated in September 2004, to stage the Coca-Cola Football League Play-Off Finals at the Millennium Stadium in Cardiff."