London Marathon to Expand to Two-Day Event in 2027

London Marathon Events has announced that the 2027 TCS London Marathon will expand into a two-day event, allowing a record 100,000 participants to run the iconic course. Scheduled for 24th and 25th April 2027, the one-off format change aims to meet unprecedented demand, as ballot applications for the annual race have surpassed one million in recent years. The event will maintain the traditional Greenwich-to-Westminster route, with the field split across both days to accommodate the increased capacity.

Why is the London Marathon changing its format?

The decision to move to a two-day format in 2027 is a direct response to the massive growth in public interest. According to London Marathon Events, the race remains the world’s most oversubscribed marathon, with more than one million people applying for a limited number of spots in recent ballots. By doubling the number of finishers to 100,000, organizers aim to significantly increase fundraising for UK charities. The marathon currently holds the title of the world’s largest annual one-day fundraising event, with participants raising over £90 million in recent editions. Projections from event organizers suggest the 2027 “Double” could generate more than £150 million for good causes and provide a £400 million boost to the UK economy.

How will the two-day race work for runners?

The 2027 event will see the mass participation field divided across the two days, with different athlete categories leading each start. While specific scheduling for the waves is still under development, Mayor of London Sadiq Khan confirmed that the city is coordinating with emergency services and local councils to manage the infrastructure required for an expanded weekend. Participants who have already entered the ballot process will be considered for either day, though the rules strictly prohibit individuals from running both in-person events. Runners may, however, participate in one of the in-person days and concurrently join the “London Marathon MyWay” virtual event.

What is the impact on local community programs?

Beyond the primary race, the expansion includes a commitment to grassroots sports through the London Marathon Foundation. A portion of the entries will be reserved for schools and community groups throughout London. This funding model is designed to support long-term youth activity programs across the capital. This initiative builds on the existing Mini London Marathon, which provides running opportunities for children. Hugh Brasher, CEO of London Marathon Events, described the move as a “once-in-a-generation” reimagining of the event’s role in city-wide health and activity.

Key Details for 2027 Participants

• Event Dates: 24th and 25th April 2027.
• Capacity: 100,000 total participants.
• Route: The standard course from Greenwich to Westminster will be used for both days.
• Ballot Status: Current applicants will be entered into a draw for either day.
• Restrictions: Runners are limited to one in-person race entry for the weekend.

The shift to a two-day format reflects a broader trend in global mass participation sports, where organizers are increasingly adopting multi-day structures to manage safety, logistical constraints, and the rising demand for entry. While the 2027 event is currently confirmed as a one-off “Double,” the success of the logistics and the economic impact will likely serve as a benchmark for future large-scale marathon operations in major global cities.