Elite sport stars don't tend to shy away when it comes to giving back. While many are incredibly generous, some take it one step further, devoting their time to philanthropic causes, acting as charitable ambassadors, and handing over huge chunks of their fortunes to the causes close to their hearts.

From David Beckham and Serena Williams to Tiger Woods and Michael Jordan, read on to discover some of the world's most generous athletes. All dollar values in US dollars.