Former England football captain Beckham helped London win the right to organise the 2012 Games and Brazilian great Pele was part of Rio de Janeiro's successful bid for the 2016 Games.
NBA basketball player Pau Gasol is a figurehead for Madrid, competing against Istanbul and Tokyo in Saturday's International Olympic Committee vote to stage the 2020 Games.
Madrid, however, is also getting a helping hand from Argentine sports figures in Buenos Aires.
World middleweight boxing champion Sergio 'Marvel' Martinez, a Madrid resident for more than a decade, has followed Barcelona football ace Lionel Messi, also Argentine, in promoting the bid in his home city.
Martinez extolled the virtues of Madrid and Spain at a news conference on Thursday and played down the adverse effects of the world's economic crisis on the Spanish capital.
"The crisis affects the whole world, there isn't a country that escapes it but Spain is all right," the 38-year-old said.
"Anyone who comes and goes between Europe and Latin America can see the difference between a crisis in a country like Spain and a country like Argentina.
"I think Spain has an excellent infrastructure already in place and an enormous solidity in the people who are committed to working to make these the best Games," said Martinez.
"(Madrid) has the experience of having made two previous bids and they say third time lucky," he added, referring to the failed bids for 2012, when they were third behind London and Paris, and 2016 as runners-up to Rio.
"Chances grow (with each bid) and there are lots of very capable people (working for Madrid) but the most important thing for me is the generosity and warmth of the Madridian, the Spaniard."
Talking specifically of boxing at the Olympics, Martinez said the event had played an important part in the careers of leading fighters like Muhammad Ali.
"Although there are differences between amateur and professional boxing, the talented boxer as an amateur will be a talented pro," he said.
"Olympic medal winners who turn professional almost always become big names," said Martinez who won the WBC middleweight title by beating Mexican Julio Cesar Chavez Jr last year and defended it successfully against Briton Martin Murray in April.
"I didn't get to be at an Olympiad but I know it's always positive for sportspeople and boxers to take part at a Games."
- Sports & Recreation