On 8 August, more than 10,000 athletes from around 200 countries will be competing in 28 different sports to try and get their hands on at least one of the 906 Olympic medals on offer.
But with so many global sporting stars showing off their skills - who's going to end up grabbing the most headlines?
Well here are the international athletes Newsround's Olympics reporter Sonali thinks you should watch out for...
First, let's go to Jamaica. The men's 100 metre race always gets the most attention at the Olympics - and the Caribbean island of Jamaica is home to one of the fastest men on the planet -21-year-old Usain Bolt.
Usain's nickname is the Lightening Bolt!
He can run 100 metres in 9.72 seconds. No wonder his nickname is Lightening Bolt!
Next to the United States of America where double world champion sprinter Tyson Gay lives - the clash between him and the Lightning Bolt will definitely be one of the highlights of the Olympics.
Tyson Gay will be going for gold!
In fact, last week, Gay actually beat Bolt and ran the 100 metres in the fastest time ever - but because there was so much wind behind him, it didn't count as an official world record. Expect some fireworks between those two!
Argentina's basketball team won gold in the last Olympics. They're keen to defend their title, but they'd better watch out - because America has a great team now ready to boot this lot out the way to grab gold.
Natalie Du Toit is set to make history
Onto South Africa - one of their swimmers, Natalie Du Toit, is set to make history by becoming the first athlete to compete in both the Olympics and Paralympics.
She's now known as the world's best disabled sportsperson - so keep your eye out for her.
I can't not mention the host country China - their most famous athlete is 110 metre hurdles world champion and Olympic champion Liu Xiang.
Liu Xiang is a massive celeb in China!
He's a massive celebrity there - bigger than Beckham!
He gets mobbed everywhere he goes.
The hurdler will have 1.3 billion people with their fingers crossed, hoping he'll get gold again. No pressure then, eh?