London Marathon Double: 2027’s One-Off Two-Day Expansion

The London Marathon will be staged over Saturday 24 April and Sunday 25 April 2027, a one-off “Double” that will host a record 100 000 runners on the traditional Greenwich-to-Westminster course. Elite women, female para-athletes and women’s championship fields will lead one day’s mass start, with elite men and men’s categories leading the other.

Runner's World

Ballot entries for 2027 surged to between 1.3 million and 1.338 million, eclipsing the 1.133 million entries for 2026 and far outstripping the 59 830 finishers in the 2026 race. The marathon has grown from 7 747 starters in 1981 to the world’s largest one-day fundraising event, raising over £90 million for charity in 2026.

London Marathon confirms historic two-day event for 2027 after record ballot entries

The expansion is driven by London Marathon Events (LME) under chief executive Hugh Brasher. Mayor of London Sadiq Khan has publicly endorsed the plan. Transport for London and other city agencies initially voiced concerns about closing streets for two consecutive days, but later granted approval.

London Marathon to become two-day, 100,000-runner event in 2027

• Participants: 100 000 (vs ? 60 000 in 2026)

Two-day London Marathon, with 100,000 participants, confirmed for 2027

• Ballot entries: 1.33 million – 1.338 million

Two-day London Marathon, with 100,000 participants, confirmed for 2027

• Expected charity revenue: > £150 million (up from £90 million)

London Marathon to be held over two days in 2027

• Projected UK economic boost: £400 million

London Marathon to be held over two days in 2027

• Mini London Marathon (Friday 23 April): > 20 000 youth participants

London Marathon 2027 to expand for one-off two day event

Doubling the field is projected to create the largest fundraising moment in UK sport, potentially adding £60 million-plus to charitable totals. The £400 million economic uplift is expected from tourism, hospitality and related services. Additional income will be funneled through the London Marathon Foundation to youth-activity projects and to grassroots groups in each borough.

2027 London Marathon will be a two-day event, organisers announce

LME describes the Double as “a once-in-a-generation, one-time-only reimagining of what a marathon and city-wide celebration of activity can be.” The mayor called London “the sporting capital of the world” and praised the expansion as a testament to the city’s global status. Transport for London’s eventual consent reflects a balance between logistical concerns and public demand.

London Marathon to be held over two days in 2027

Transport for London and other stakeholders initially warned that shutting down the capital for two days could strain transport networks and emergency services. Their reservations centered on traffic disruption, public safety and the feasibility of managing double the usual crowd.

TCS London Marathon will be a two-day event in 2027, but organisers say it’s for one year only

Sources differ on the exact ballot figure: some cite “1.33 million,” others “1.338 544 million,” while a few round it to “1.3 million.” Additionally, estimates of the public-lottery selection chance vary between 7 % and 7.5 %. No official breakdown of charity-allocated versus corporate-sponsored entries has been released.

Two-day London Marathon, with 100,000 participants, confirmed for 2027

• “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.” — Hugh Brasher, CEO, London Marathon Events

London Marathon 2027 to expand for one-off two day event

• “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. We believe that more than £150m can be raised for good causes and the UK economy will have a £400m social and economic benefit.” — Hugh Brasher

The Guardian

• “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.” — Sadiq Khan, Mayor of London

London Marathon to expand to two-day record-setting event in 2027

• “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.” — Sadiq Khan

The Guardian

Ballot results will be announced in early July 2026, assigning successful applicants to either Saturday or Sunday. The two-day format is confirmed as a one-off experiment; the marathon will revert to a single-day race in 2028 unless future demand prompts further changes. Preparations continue on route logistics, security and the expanded week-long festival of events surrounding the Double.

TCS London Marathon will be a two-day event in 2027, but organisers say it’s for one year only