Get your running shoes and Lycra ready because we’ve scoured the UK for the very best races of 2025, from iconic marathons to unique triathlons and must-try duathlons. Whether you’re after a PB in a big-city marathon, fancy a scenic triathlon along the coast, or want to go off-road on mountain trails, these 21 events are a mix of the biggies you’ve heard of and a few below-the-radar gems that’ll make your training miles totally worth it. So, pin this list, mark your calendar, and get ready to sweat in style!

1. Great Welsh Marathon

Where? Carmarthenshire, Wales

When? 16 March 2025

Why? Step aside London, Wales’ oldest marathon is where the PB chasers are headed. Picture this: stunning coastal parkland, a traffic-free trail, and a route so flat you could practically run it on rollers. Ideal for newbies and seasoned runners alike.

2. Ashridge Duathlon

Where? Ashridge House, Hertfordshire

When? 23 March 2025

Why? Dreaming of multisport? This duathlon through the gorgeous Ashridge Estate offers a 10K run, 44K bike ride, and a 5K run to finish – the perfect way to dust off winter cobwebs and launch your season in style.

3. Brighton Marathon

Where? Brighton, England

When? 6 April 2025

Why? Sun, sea, and spectator-packed streets. This big-city marathon along Brighton’s famous seafront is a party in running shoes, with carnival vibes, thousands of supporters, and a mostly flat course made for fast times.

4. Rat Race Ultra Tour of Arran

Where? Isle of Arran, Scotland

When? 5-6 April 2025

Why? Ready to take on “Scotland in miniature”? The Rat Race Ultra Tour of Arran is a two-day, 60-mile trail adventure across mountains, glens, and rugged coastlines. Expect serious climbs, jaw-dropping views, and enough scenic challenges to keep even seasoned trail runners on their toes. Not for the faint-hearted but pure heaven for trail junkies!

5. Bamburgh Castle Duathlon

When? 13 April 2025

Where? Bamburgh Castle, Northumberland

Why? A breathtaking duathlon at the iconic Bamburgh Castle! Run on scenic trails around the castle grounds, then cycle along the breathtaking Northumberland coast. Choose from Sprint or Standard distances, or team up with friends for a relay. With the transition area on the castle’s front Green, you won’t find a more stunning race setting in the UK.

6. Manchester Marathon

Where? Manchester, England

When? 27 April 2025

Why? The UK’s flattest, fastest city marathon! Perfect for first-timers or anyone craving a PB, this closed-road race combines big-race energy with a feel-good festival atmosphere.

7. Blackpool Marathon

Where? Blackpool, England

When? 27 April 2025

Why? Seaside vibes for the whole family! Pass by Blackpool Tower, enjoy the ocean breeze, and soak up that famous spring sunshine – this is the marathon for a spring PB and beachy fun.

8. Great Birmingham Run

Where? Birmingham, England

When? 4 May 2025

Why? With both half marathon and 10K options, the Great Birmingham Run winds through the city’s iconic spots, including the stunning canals and buzzing streets. Expect cheering crowds, top-notch entertainment, and a festival finish line atmosphere. Whether you’re chasing a PB or just enjoying the ride, this is Brum at its best – lace up and join the fun.

9. Milton Keynes Marathon

Where? Milton Keynes, England

When? 4-5 May 2025

Why? Bucks’ biggest running event is here! Start with the Rocket 5K on Sunday, then tackle the Marathon, Half Marathon, or Relay on Monday – or do both for the MK Challenge medal. Add in a Superhero Fun Run for all ages and finish in style at StadiumMK, cheered on by thousands.

10. Edinburgh Marathon

Where? Edinburgh, Scotland

When? 25 May 2025

Why? Edinburgh’s Marathon festival weekend and flat coastal route make this Scotland’s answer to the big city marathon but with races all weekend from 1k to 50k, there’s something for everyone . Fast, scenic, and sold-out year after year – you’ll need to be quick off the blocks to nab a spot.

11. Celtman Extreme Triathlon

Where? Torridon, Scotland

When? 14 June 2025

Why? Not for the faint-hearted, this extreme triathlon on Scotland’s rugged west coast is a test of true grit – with a mountain run that’ll make you feel invincible.

12. Blenheim Palace Triathlon

Where? Blenheim, Oxfordshire

When? 7-8 June 2025

Why? Want a multisport taster in a stunning setting? Blenheim offers a lovely, beginner-friendly triathlon option, perfect for a summer’s day with friends and family cheering you on.

13. Croyde Ocean Triathlon

Where? Croyde, Devon

When? 6 July 2025

Why? Coastal lovers, rejoice! This triathlon boasts a scenic 37K bike ride and hills galore. Think ocean views, lush Devon hills, and a race so beautiful you won’t want it to end.

14. Outlaw Triathlon

Where? Nottingham, England

When? 26-27 July 2025

Why? Outlaw is known for its stellar support and flat, smooth course – perfect for long-distance tri newbies wanting to tackle that 140.6 miles in a friendly setting.

15. New Forest Marathon

Where? Brockenhurst, England

When? 14 September 2025

Why? Run through ancient woodland, past ponies, and through quaint villages in the gorgeous New Forest. A firm fave for nature-loving runners.

16. Loch Ness Marathon

Where? Inverness, Scotland

When? 28 September 2025

Why? Scenic, legendary, and a tad spooky – Loch Ness is the marathon to run if you’re into mythical monsters, Scottish hospitality, and jaw-dropping views.

17. Isle of Wight Marathon

Where? Isle of Wight, England

When? 5 October 2025

Why? A historic, undulating route that’s been going strong since 1957. Expect sea views, rolling hills, and a good dose of island charm.

18. Kielder Marathon

Where? Kielder, Northumberland

When? 5 October 2025

Why? Dubbed ‘Britain’s Most Beautiful Marathon’, the Kielder Marathon Weekend is packed with stunning races for all ages and abilities. Kick things off with a 10K & Gravel Duathlon on Saturday, followed by Sunday’s Half Marathon and Junior races, leading up to the marathon finale. Expect an electric atmosphere and unforgettable views in one of the UK’s most scenic spots

19. Portsmouth Coastal Marathon

Where? Portsmouth, England

When? 21 December 2025

Why? Cap off your year with a flat, seaside marathon. With holiday cheer and coastal views, this multi-terrain race is the perfect way to run off the Christmas treats.