London Marathon Will Run Across Two Days in 2027, Expanding the Field to 100,000 Runners

The TCS London Marathon will run on two consecutive days for the first time in its 46-year history, organisers announced Friday, expanding the field to 100,000 runners and creating what is expected to be the largest single charity fundraising event ever staged in the UK.

London Marathon Events confirmed the 2027 race will take place on Saturday 24 April and Sunday 25 April. The change applies only to that edition. Runners will follow the standard course from Greenwich to Westminster on both days.

The decision follows record-breaking demand. A total of 1.33 million people entered the ballot for the 2027 race, far exceeding the field size of any previous edition. The 2025 marathon was recognised as the No. 1 marathon brand in the world, and the event held that ranking through 2026.

“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 the organisation expects the weekend to raise more than £150 million for charity and deliver £400 million in social and economic benefit to the UK.

The London Marathon has been a fundraising fixture since the first race on 29 March 1981. The 2026 event raised more than £90 million for charity, and the marathon has now generated £1.4 billion for good causes over its lifetime. The 2027 official charity of the year is the National Autistic Society.

How the race will be split

Elite competition will be divided between the two days. Elite women, elite female para-athletes, championship runners and “good for age” women will lead the mass race on one day. Elite men, elite male para-athletes, championship runners and “good for age” men will lead the field on the other. Organisers said which group races on Saturday and which on Sunday will be confirmed in the coming months.

Anyone who already entered the 2027 ballot will be considered for both Saturday and Sunday. Allocation will be random. Runners cannot race in person on both days, but those who secure a place can also take part in the virtual TCS London Marathon MyWay event on the day they are not running. Ballot results will be released in early July.

A statement from City Hall

Mayor of London Sadiq Khan welcomed the announcement and pledged continued cooperation between the Greater London Authority and race organisers.

“London is the sporting capital of the world and I am delighted that, for one year only in 2027, the world famous TCS London Marathon will expand into a two-day event,” Khan said. “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.”

Khan said his office would continue working with London Marathon Events, councils on the route and the emergency services to plan for the expanded weekend.

What runners need to know

The 26.2-mile route will remain unchanged. The start areas in Greenwich and the finish line on The Mall will operate on both days. Closures, transport adjustments and event-day logistics will be published closer to race weekend. Runners can revisit our London Marathon overview and mile-by-mile race execution plan when building a strategy.

The Double will close out a longer week of TCS London Marathon events, starting with an extended Running Show and the TCS London Marathon & Friday Night Lights 5K. After 2027, the marathon is expected to return to its usual one-day format.

Marathon Handbook first reported on the two-day plans earlier this year. For runners hoping to be among the 100,000, the ballot remains the primary route in. Organisers stressed that the format change does not guarantee a place to any existing applicant, and that allocation across both days will be drawn at random.