Prime Minister Gordon Brown congratulated Rio after it was announced the city would host the 2016 Olympic Games.
He said: "I know very well the pride and excitement the people of Rio, and indeed the whole of Brazil, will be feeling at the prospect of having the Olympics on home soil.
"Each games is unique and every city brings its own passion and vision to this monumental event. I have no doubt that Rio will make its own special contribution and make its own mark on this historic competition.
"We look forward to working closely with Rio de Janeiro in the coming months and years on these sporting celebrations."
The Brazilian city beat competition from Madrid, Chicago and Tokyo to land the sporting extravaganza. The decision was announced by International Olympic Committee (IOC) president Jacques Rogge in Copenhagen.
The announcement, which sees the games go to South America for the first time, sparked wild celebrations in Denmark and Brazil.
Mr Rogge said: "All four projects are of the highest quality - thank you for your hard work, energy and commitment. But in every competition there can only be one winner."
Athlete Denise Lewis, who won gold at the 2000 Sydney Olympics, said it was the right decision.
She said: "I think it is fantastic. Every Olympiad, you want the Olympic movement to move forward and venture into uncharted territory."
Chicago had been favourite to land the games, with its odds bolstered after US president Barack Obama flew in to the Danish capital to help with the final bid presentation.
