London Marathon. Photo: Tartezy / Shutterstock.com The London Marathon will expand into a two-day event in 2027 for the first time in its history, allowing a record 100,000 participants to take part across the weekend in what organizers are calling a one-off transformation of the world-famous race.
The announcement marks a major change for one of the most iconic events in global sport, which has traditionally taken place over a single day. The expansion will see the marathon staged on Saturday, April 24, and Sunday, April 25, 2027, with runners spread across both days on the same classic route from Greenwich to Westminster.
London Marathon. Photo: Sampajano / Shutterstock.comLondon Mayor Sadiq Khan welcomed the decision, saying it reflects the capital’s global sporting status. He said London is “the sporting capital of the world” and described the expanded format as a unique opportunity for more people to take part in the landmark event.
Organizers said the decision comes in response to overwhelming demand. Earlier this year, more than 1.33 million people entered the ballot for the 2027 race, breaking previous records and highlighting the growing popularity of the event worldwide.
All applicants for the 2027 race will be entered into a ballot covering both days, with results expected in early July. Organizers plan to run separate draws for the Sunday and Saturday events, with Sunday entries selected first, followed by Saturday allocations.
The structure of the weekend will also split elite and mass participation fields across both days, although final details are still being confirmed. Organizers have indicated that elite women, wheelchair athletes, and women’s mass participation groups will feature on one day, while elite men, wheelchair athletes, and men’s mass participation groups will compete on the other.
London Marathon. Photo:Stephen Noulton / Shutterstock.com The expansion builds on a record-breaking year for the event. The 2026 London Marathon saw nearly 60,000 finishers and has already raised more than £90 million for charity, making it one of the largest fundraising events in the world.
The 2027 edition will also include the Mini London Marathon on Friday, with more than 20,000 young participants expected to take part.
While organizers confirmed the two-day format is intended as a one-off experiment, they said all additional income generated will be directed through the London Marathon Foundation to support youth activity projects across London and the United Kingdom.
The move positions the 2027 race as the largest edition in the marathon’s history, both in participation and in fundraising impact.