London Marathon Is Planning a Two-Day, 100,000-Runner Event in 2027

If you’ve ever opened a London Marathon rejection email with a resigned sigh, this one’s for you.

The Guardian reported Wednesday that the London Marathon is in serious talks to stage a two-day event in April 2027 — one that would allow 100,000 runners to race across one of the world’s most iconic courses, double the current capacity in a single shot.

Referred to internally as the “Double London Marathon,” the proposal would split the field across two days: 50,000 runners on Saturday April 24, and another 50,000 on Sunday April 25. It hasn’t received formal approval yet, but the Guardian says it has the backing of the mayor of London’s office.

A ballot that’s become almost impossible to win

To understand why this matters, consider the numbers. More than 1.1 million people entered the ballot for the 2026 London Marathon. Three years ago, that figure was 410,000. The race hasn’t gotten significantly bigger — the odds have just gotten a lot worse.

Doubling the field, even as a one-off, would give hundreds of thousands of runners who’ve been bounced from the ballot a genuine shot at one of the six World Marathon Majors. For anyone who’s been trying and failing for years, that’s a significant deal.

The fundraising angle is equally compelling. In 2025, a record 56,540 finishers raised £87.3 million for charity — already making London the world’s largest annual one-day fundraising event. Organizers hope a 2027 two-day format would push that figure past £130 million.

What the race is (and isn’t) saying

The London Marathon declined to confirm the plans when the Guardian approached them for comment. But chief executive Hugh Brasher offered a statement that wasn’t exactly a denial either.

“The TCS London Marathon is the world’s most popular marathon, and we are always exploring innovative ways to enable more people to take part and to deliver positive benefits for London,” he said.

He also invoked the race’s founding spirit: “We are looking forward to amplifying one of the original aims of the London Marathon, which was ‘to show happiness and sense of achievement in a somewhat troubled world.’ Poignantly, those words resonate even more now than they did almost 45 years ago.”

Read into that what you will.

The elite races would change too

It’s not just the masses who’d see a different race. Under the proposal, the elite men’s and women’s races would also be held on separate days — giving each field its own spotlight rather than sharing a Sunday. For spectators, that’s potentially two distinct race-day experiences along the route through Greenwich, Tower Bridge, and the Mall.

Splitting the elite fields could also change the media and broadcast dynamic considerably, giving TV coverage a full day to dedicate to each race rather than fitting both into a single Sunday broadcast window.

For now, 2026 comes first

The Guardian reports that a series of meetings have already taken place with various stakeholders, which suggests these conversations are well beyond idle speculation. Part of the proposal is also framed around unity and community — a two-day event positioned as a statement at a time of growing social and economic division in Britain.

But the immediate focus remains on the 2026 TCS London Marathon, taking place Sunday April 26 — now just four weeks away. If you’re still chasing a World Marathon Major entry, it’s also worth knowing the Good for Age standards tightened for 2026. If the 2027 plans come together, it could mark the most ambitious change in the race’s 45-year history.

That’s quite the birthday present.