The streets of London were busy on Sunday with 35,000 runners pounding the pavements.
The sun was shining when the professional athletes kicked off the race in Blackheath, in south-east London.
Meanwhile, the rest of the runners set off from the city's Greenwich Park.
Lots of people took on the challenge to raise money for charity.
Six Masai warriors, hoping to raise £600 for clean water for their home in Tanzania, left enough time for singing and dancing along the way!
And lots of the runners were dressed up in colourful costumes...
If you looked carefully, there were even some superheroes taking part!
Twenty-six miles was probably nothing for this runner!
Is there anything in the rules to say you can't fly the race?
TV chef Gordon Ramsay certainly needed to cool off when he crossed the finish line!