The Duke of Cambridge said London's staging of the Champions League final would inspire a generation through its "excellence" as he welcomed delegates to Uefa's 37th annual congress.
William declared himself "first and foremost" a football fan as he gave the opening speech at the annual conference of European football's governing body.
Tomorrow, Wembley Stadium will host the showpiece final of Europe's premier competition between Germany's two leading teams, Borussia Dortmund and Bayern Munich.
The Duke of Cambridge, who is president of English football's governing body the Football Association (FA), joked about who he thought would win the eagerly anticipated final.
He told delegates: "It is a great honour for us, the English FA, to host not just this prestigious congress, but of course - the real excitement - tomorrow's Champions League final.
My money is on Bayern Munich and two-nil. To host these events during our 150th anniversary year is truly special."
He went onto say: "Events like tomorrow's match are hugely important because they inspire through their excellence.
But what really counts is the work you all do at a grassroots level - investing in facilities; training coaches; and addressing discrimination to make the game open to everyone.
I know some of these issues are on your agenda today, and I welcome Uefa's determination to continue to improve European football for all."
Mayor of London, Boris Johnson, says he's delighted that the football festival will be held in Stratford.
Football fans attending the free festival will be able to visit a "Champions League museum", featuring memorabilia from previous tournaments, and have their photos taken with the competition trophy.
Coaching courses will also be available for children and former England players Faye White and Steve McManaman will be meeting and greeting fans as festival ambassadors.
Meanwhile, an "Ultimate Champions Match" will feature a number of Champions League greats of years gone by.
The festival will coincide with the UEFA Champions League final, which is taking place at Wembley on Saturday 25th May.
Plans for a four-day football festival this summer have been unveiled.
The UEFA Champions Festival will take place between 23 and 26 May at the International Quarter - next to the Olympic Park in Stratford.
European football's governing body UEFA could take action after claims that racist chants were made at Thursday night's match between Tottenham and Lazio at White Hart Lane.
Three Spurs players were apparently targeted by some of the Italian club's supporters.
It has also emerged that a Chelsea player has also been racially abused. Chelsea manager Roberto Di Matteo and Arsenal manager Arsene Wenger have said racism in football must stop.
Chelsea captain John Terry will be allowed to lift the trophy, if they beat Bayern Munich, even though he's banned from playing the Champions League Final.
He was shown a red card for kneeing Alexis Sanchez in the back during Chelsea's 2-2 draw at Barcelona, in the semi-final second leg.
That sent them through to the final in Munich on the 19th of May. Uefa said today that Terry will be allowed to lift the trophy and collect a medal.