The London Marathon will be held as a two-day event for the first time on Saturday, April 24, and Sunday, April 25, 2027 [1, 2, 3]. Organisers announced the 'Double' marathon as a unique, once-in-a-generation experiment designed to accommodate a record 100,000 runners across the two days, nearly doubling previous event participation [1, 2, 3].

More than 1.33 million people entered the ballot for a place in the 2027 race, setting a new record for marathon entries [2, 3]. Runners will be selected by ballot in early July and cannot compete on both days [1, 2].

The event schedule will split elite athletes and mass participants by gender. The elite women, elite female para-athletes, championship runners, and good-for-age women will run alongside around 50,000 mass runners on one day [1]. The elite men will headline the other day with a similar programme including a second mass participation event [1].

Hugh Brasher, Chief Executive of London Marathon Events, called the Double marathon "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." He said expanding to 100,000 runners will open doors for more people, charities, and communities, and expects more than £150 million to be raised for good causes with a £400 million social and economic boost for the UK economy [2].

The 2026 London Marathon, held as a one-day event on April 24, saw a record 59,830 finishers and raised over £90 million for charity [2, 3]. Kenya's Sebastian Sawe became the first athlete to complete the course in under two hours with a time of 1:59:30 [2, 3].

London Mayor Sadiq Khan welcomed the two-day event as "a unique sporting occasion" and praised its potential for economic and charitable impact, calling London "the sporting capital of the world." He called the 2027 double "the largest fundraising moment in UK sporting history," supporting many charities [2, 3].

Ballot results naming the runners accepted for the 2027 marathon are expected in early July 2026 [1, 2]. The event will take place on April 24 and 25, 2027, marking the first and only time the London Marathon is held over two days [1, 2, 3].