The London Marathon is an annual marathon held in London, United Kingdom. It was founded by athletes Chris Brasher and John Disley in 1981. It is usually held in April, but the 2021 and 2022 events were moved to October due to the COVID-19 pandemic. The largely flat course is set around the River Thames. It starts in Blackheath and finishes at The Mall.

The 2026 London Marathon set many new world records. 59,830 people competed, making it the largest marathon in the world. Winner Sabastian Sawe from Kenya and a second runner, Yomif Kejelcha from Ethiopia, finished in under two hours. This was the first time anyone ran a marathon in under two hours. Tigst Assefa from Ethiopia set a new world record for women.