London Goes Big: The 2027 Marathon Becomes a Two-Day, 100,000-Runner Event
Announced 19 June 2026: the TCS London Marathon 2027 will be a one-off two-day event on 24–25 April, with 100,000 runners crossing the finish on The Mall. The elite women lead Saturday and the elite men lead Sunday, after a record 1.33 million people entered the ballot.
What happened
The biggest marathon in the world just decided to get twice as big. On 19 June 2026, London Marathon Events confirmed that the TCS London Marathon 2027 will be staged across two days — Saturday 24 and Sunday 25 April 2027 — in a one-off format that will let a record 100,000 runners cross the famous finish line on The Mall.
Both days run the same iconic 26.2-mile route from Greenwich to Westminster. Organisers are calling it their "most ambitious evolution to date" — and the numbers behind the decision explain why.
Why two days
This is a story about demand the race simply could not meet. A staggering 1.33 million people entered the ballot for the 2027 race — the largest number of applicants any marathon has ever received. London is already the world's biggest marathon by finishers; a single Sunday physically cannot hold the appetite for it.
Splitting the race across a weekend nearly doubles the field. Ballot runners will be randomly assigned to either the Saturday or the Sunday race, with results announced in July. Same route, same finish, same crowds — just two chances to be out there.
"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," said Hugh Brasher, CEO of London Marathon Events.
The detail runners will love
Here's the part that makes this more than a logistics fix: the two days have been built around the elite races in a way that finally gives the women their own stage.
- Saturday will be led by the elite women, the elite women's para-athletes, and the championship and 'good for age' women.
- Sunday will be led by the elite men, the elite men's para-athletes, and the championship and 'good for age' men.
For years, elite women's marathoning has fought to be seen on its own terms rather than as the warm-up act to the men. London's split hands the women a dedicated day with the full glare of the broadcast on them alone — a quietly significant moment for the sport.
The bigger picture
The scale here is hard to overstate. Organisers expect the weekend to raise more than £150 million for good causes — what Mayor of London Sadiq Khan called "the largest fundraising moment in UK sporting history" — and to deliver around £400 million in social and economic benefit to the UK.
London has spent the last few years pulling away from the pack. It overtook New York to become the world's largest marathon, then kept breaking its own record. A 100,000-runner weekend doesn't just extend that lead — it redraws what the ceiling for a city marathon even looks like.
What it means if you're watching from here
London is one of the seven long-standing Abbott World Marathon Majors — and, as of this month, Cape Town has joined the series as the eighth, the first on African soil. For South African runners, the Majors map has never looked more reachable.
A few honest notes if a Major weekend is creeping onto your dream list:
- The ballot is brutal, and now bigger than ever. 1.33 million applicants for 2027 tells you the odds. Treat a Major as a multi-year goal, not next April's plan — and remember a charity place is often the more reliable route in.
- You don't start at 42.2 km. Every one of those 100,000 runners has a first 5K behind them. If London lit the fire, start where it actually begins — our first 5K guide is built for exactly that.
- There's a start line closer than London. While you build, find a race near you and bank the experience. The Mall will still be there.
Two days, 100,000 runners, one finish line. The world's biggest marathon just got bigger — and the door it's opening is wider than ever.