London's successful bid to host the 2012 Olympic Games will see eight football matches staged at the Millennium Stadium in Cardiff.
The venue's chief executive, Paul Sergeant, said: "We are thrilled to play a part in staging the Olympics.
"I am sure everyone is Wales will echo that. We backed the bid and now we will back its total success."
There is also the possibility that Welsh training facilities will be used by cyclists and swimmers.
Newport has the National Velodrome, while the National Pool in Swansea is a brand-new aquatic complex.
London won a two-way fight with Paris by 54 votes to 50 at the IOC meeting in Singapore, after bids from Moscow, New York and Madrid were eliminated.
Paris had been favourites throughout the campaign but London's hopes were raised after an impressive presentation by Lord Coe, the bid chairman.
"London put on a fantastic presentation, delivered brilliantly by Lord Coe and his team and showed a huge amount of heart and passion which is what the Olympics are all about," Sergeant added.