The London Marathon is set to make history in 2027 by becoming a two-day event for the first time, giving thousands more runners the chance to take part while creating what is expected to be the biggest fundraising weekend in UK sporting history.

Taking place on Saturday 24 and Sunday 25 April 2027, the special one-off event will welcome 100,000 participants across the weekend. The expanded format has been introduced after a record 1.33 million people entered the public ballot, highlighting the extraordinary demand for places.

Organisers say the additional capacity will allow more charities, community groups and local runners to experience one of the world’s most famous marathons.

More Places for Communities and Charities

Every London borough along the marathon route, stretching from Greenwich to Westminster, will receive extra guaranteed entries. The move is designed to support grassroots organisations and local charities, helping them raise vital funds while encouraging greater community participation.

Money generated from the additional runners will be distributed through the London Marathon Foundation, funding projects that encourage children and young people across London and the UK to become more active.

The expanded event is expected to raise more than £150 million for good causes, significantly surpassing previous fundraising records.

National Autistic Society Set for Record-Breaking Fundraising

The National Autistic Society, announced earlier this year as the official Charity of the Year for the 2027 event, is one of the biggest beneficiaries of the expanded format.

Originally allocated 250 marathon places with a fundraising target of £2 million, the charity will now field around 1,000 runners and expects to raise approximately £3.75 million.

Chief Executive Caroline Stevens described the announcement as an incredible opportunity to support autistic people and their families while increasing public understanding of autism.

She said the larger event would allow the charity to celebrate its biggest-ever London Marathon team, with hundreds more participants helping to raise essential funds and awareness.

The London Marathon already holds the title of the world’s largest annual one-day fundraising event. This year’s race raised more than £90 million for charities and saw almost 60,000 runners cross the finish line.

Hugh Brasher, Chief Executive of London Marathon Events, called the 2027 expansion the event’s “most ambitious evolution to date” and described it as a once-in-a-generation opportunity to bring together more people, more charities and more communities.

The Mayor of London, Sadiq Khan, welcomed the plans, describing the event as a unique opportunity to create the largest fundraising moment in UK sporting history.

Alongside the expected £150 million charitable impact, organisers estimate the two-day marathon will deliver around £400 million in wider social and economic benefits for the UK.