The 2017 London Marathon was the 37th running of the annual marathon race in London, England, which took place on Sunday, 23 April. Mary Jepkosgei Keitany won the women's race, setting a new women-only marathon world record with a time of 2:17:01, while Daniel Wanjiru came first in the men's race in 2:05:48. David Weir claimed a record breaking seventh win at the London Marathon in the men's wheelchair event. The win broke a tie between Weir and Tanni Gray Thompson for the most wins at the London Marathon.

The London Marathon is an annual marathon held in London, England. It is the largest marathon in the world, with over 53,700 finishers in 2024, and 840,318 applicants for the 2025 event. Founded by athletes Chris Brasher and John Disley in 1981, it is typically held in April, although it moved to October for 2020, 2021, and 2022 due to the COVID-19 pandemic. The largely flat course is set around the River Thames, starting in Blackheath and finishing at The Mall. Hugh Brasher is the current race director and Nick Bitel its chief executive.