LONDON — The London Marathon will expand to a two-day event in April 2027, with a single-year format. Organizers plan for 100,000 runners to participate across Saturday, April 24, and Sunday, April 25.

"The 2027 TCS London Marathon Double is our most ambitious evolution to date – a once-in-a-generation one-time-only reimagining of what a marathon and city-wide celebration of activity can be," said Hugh Brasher, chief executive of London Marathon Events. "By expanding to 100,000 runners across two days, we're opening the door for more people, more charities and more communities to take part in the world's greatest marathon," Brasher said. A total of 1,338,544 individuals applied for the 2027 ballot, which exceeded the previous record of 1,133,813 applications for the 2026 event.

All participants will run the standard marathon route from Greenwich to Westminster. Runners who receive a ballot entry will not be permitted to compete on both days of the event. Ballot results for the 2027 event will be announced in early July, with a ballot draw for Sunday participants occurring before a second draw for Saturday participants.

Elite women, elite female para-athletes, championship women, and "good for age" women will compete alongside a mass participation field on one day. Elite men, elite male para-athletes, championship men, and "good for age" men will compete with a mass participation field on the other day.

"This unique, one-off double will allow a record 100,000 participants to take part across the two days – creating the largest fundraising moment in UK sporting history and supporting the work of so many incredible charities," said Sadiq Khan, Mayor of London. Every school in London will receive two guaranteed ballot entries for teachers or staff for the 2027 race, and guaranteed ballot entries have been allocated to each London borough situated along the race route.