100K ultra runs

100K ultra runs

The UK's most comprehensive calendar of 100K ultra runs - a serious endurance challenge at over 60 miles and taking a full day to complete! Search by date, location or map to find a 100K ultra marathon near you or browse to discover your perfect event.

View all 100K ultra runs

100K ultra runs in the UK

The middle of the common ultra distances at just over 60 miles, 100K ultra marathons are a big step up from the marathon. Despite this, distance is not always the key challenge with ultra runs - the total ascent gives a much better indication of how hard it will be. Select your location to find 100K ultra runs in your area or scroll down to browse events coming up.

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100K ultra runs in 2025

Featured events are listed below - select a month/region or the map view to see all events.

Walk, jog or run along the spectacular UNESCO World Heritage coastline from Corfe Castle past Lulworth Cove and Durdle Door, with full support, welcoming base camp and finish line celebration!
  • Sat 17 - Sun 18 May
  • £39-£199
Wareham, Dorset, UK

Jurassic Coast Ultra Challenge

Walk, jog or run along the spectacular UNESCO World Heritage coastline from Corfe Castle past Lulworth Cove and Durdle Door, with full support, welcoming base camp and finish line celebration!

  • Trail run 2
  • 50K ultra run 2
  • 100K ultra run 2
  • Marathon
  • Ultra run
  • + 1 more race
  • Families
  • Newcomers
  • Entertainment
  • Music
  • Event village
  • Rural
  • Coast
  • Age 14 & over
  • Runs
Walk, jog or run the capital-to-coast route with 2,000 other adventurers over a range of distance options available and superb support all the way, for all abilities and experience levels.
  • Sat 24 - Sun 25 May
  • £89-£199
Brighton, East Sussex, UK

London 2 Brighton Ultra Challenge

Walk, jog or run the capital-to-coast route with 2,000 other adventurers over a range of distance options available and superb support all the way, for all abilities and experience levels.

  • Trail run 3
  • Ultra run 2
  • Marathon
  • 100K ultra run 2
  • Families
  • Newcomers
  • Entertainment
  • Event village
  • Age 14 & over
  • Runs
Take on England’s finest countryside at your own pace with stunning views all the way, featuring the Garburn Pass, historic Ambleside, a halfway point by Lake Windermere, forests and nature reserves.
  • Sat 7 - Sun 8 Jun
  • £39-£199
Kendal, Cumbria, UK

Lake District Ultra Challenge

Take on England’s finest countryside at your own pace with stunning views all the way, featuring the Garburn Pass, historic Ambleside, a halfway point by Lake Windermere, forests and nature reserves.

  • Trail run 2
  • 50K ultra run 2
  • 100K ultra run 2
  • Marathon
  • Families
  • Newcomers
  • Entertainment
  • Music
  • Enter online
  • Fundraising required
  • Event village
  • Urban
  • Rural
  • Age 14 & over
  • Runs
Challenge yourself in the rolling hills of the Cotswolds featuring the Cotswold Way itself, villages, footpaths and trails with fabulous views on route plus full support and hospitality.
  • Sat 21 - Sun 22 Jun
  • £39-£199
Cirencester, Gloucestershire, UK

Cotswold Way Ultra Challenge

Challenge yourself in the rolling hills of the Cotswolds featuring the Cotswold Way itself, villages, footpaths and trails with fabulous views on route plus full support and hospitality.

  • Trail run 2
  • Ultra run 4
  • 100K ultra run
  • 10K run
  • Families
  • Newcomers
  • Entertainment
  • Music
  • Event village
  • Urban
  • Rural
  • Age 14 & over
  • Runs
Take on the full 100K Race to the King ultra marathon challenge in one go. Fully supported through day and night on a route combining castles and coastal scenery.
  • Sat 21 Jun
  • £170-£180
Chichester, West Sussex, UK

Race to the King | 100K

Take on the full 100K Race to the King ultra marathon challenge in one go. Fully supported through day and night on a route combining castles and coastal scenery.

  • 100 km trail running + 4619 ft ascent
  • Chip timing
  • Enter online
  • GPS tracking
  • Undulating
  • Age 18 & over
  • 100K ultra runs
From the idyllic basecamp hub in Bakewell, charity challengers will head into the fabulous Peak District National Park on a route from 10 miles right up to the full 100km with full support!
  • Sat 28 - Sun 29 Jun
  • £39-£199
Bakewell, Derbyshire, UK

Peak District Ultra Challenge

From the idyllic basecamp hub in Bakewell, charity challengers will head into the fabulous Peak District National Park on a route from 10 miles right up to the full 100km with full support!

  • Ultra run 3
  • 100K ultra run 2
  • Trail run 2
  • Families
  • Newcomers
  • Entertainment
  • Music
  • Event village
  • Rural
  • Age 14 & over
  • Runs
Conquer Britain's oldest trail, the ancient Ridgeway, at the UK's biggest ultramarathon as you race towards the 5000-year-old Avebury Standing Stones. Back for the 12th Year Running!
  • Sat 12 - Sun 13 Jul
  • £85-£270
Watlington, Oxfordshire, UK

Race to the Stones

Conquer Britain's oldest trail, the ancient Ridgeway, at the UK's biggest ultramarathon as you race towards the 5000-year-old Avebury Standing Stones. Back for the 12th Year Running!

  • 50K ultra run 2
  • 100K ultra run 3
  • Families
  • Recycling
  • Newcomers
  • Event village
  • Rural
  • Sustainability policy
  • Public transport links
  • Age 18 & over
  • Runs
Yr Wyddfa (Snowdon) is the highest mountain in England and Wales. Your challenge is to ascend and descend as many times as possible in 24 hours - solo or as a relay team.
  • Sat 12 - Sun 13 Jul
  • £121.99-£251.99
Caernarfon, Gwynedd, UK

Black Diamond Yr Wyddfa Snowdon24

Yr Wyddfa (Snowdon) is the highest mountain in England and Wales. Your challenge is to ascend and descend as many times as possible in 24 hours - solo or as a relay team.

  • 24 hrs trail running
  • Chip timing
  • Enter online
  • Mountainous
  • Relay
  • Age 18 & over
  • Ultra runs
A new Ultra Challenge for this year, set on the stunning Gower Peninsula – the UK’s first Area of Outstanding Natural Beauty and famous for its golden beaches.
  • Sat 19 - Sun 20 Jul
  • £39-£199
Swansea, West Glamorgan, UK

Gower Peninsula Ultra Challenge

A new Ultra Challenge for this year, set on the stunning Gower Peninsula – the UK’s first Area of Outstanding Natural Beauty and famous for its golden beaches.

  • 100K ultra run 2
  • Ultra run
  • 50K ultra run 2
  • Marathon
  • Multi-terrain run
  • + 1 more race
  • Newcomers
  • Entertainment
  • Event village
  • Rural
  • Age 8 & over
  • Runs
The South Downs National Park is a superb backdrop for a real challenge featuring Beachy Head, the Seven Sisters and the South Downs Way with a choice of distances from 25km right up to 100km!
  • Sat 6 - Sun 7 Sep
  • £89-£199
Polegate, East Sussex, UK

South Coast Ultra Challenge

The South Downs National Park is a superb backdrop for a real challenge featuring Beachy Head, the Seven Sisters and the South Downs Way with a choice of distances from 25km right up to 100km!

  • 100K ultra run 2
  • Ultra run 2
  • Trail run
  • Families
  • Newcomers
  • Music
  • Event village
  • Urban
  • Rural
  • Coast
  • Age 14 & over
  • Runs
England’s greatest river provides a fantastic backdrop for an unforgettable 'festival' challenge weekend, with distances from 10km right up to 100km there’s a Thames Challenge for everyone!
  • Fri 12 - Sun 14 Sep
  • £39-£199
London, UK

Thames Path Ultra Challenge

England’s greatest river provides a fantastic backdrop for an unforgettable 'festival' challenge weekend, with distances from 10km right up to 100km there’s a Thames Challenge for everyone!

  • 100K ultra run 2
  • 50K ultra run 2
  • Trail run 4
  • Ultra run
  • 10K run
  • + 4 more races
  • Families
  • Newcomers
  • Entertainment
  • Music
  • Event village
  • Urban
  • Rural
  • Age 14 & over
  • Events
  • Sat 23 Aug
  • £90-£108
Melrose, Scottish Borders, UK

Run the Borders | Full 109K

Visiting the heartland of the Scottish Borders, runners and walkers will take to the Borders Abbey Way to complete the full waymarked loop as individuals, teams or a relay of four.

  • 109 km trail running
  • Chip timing
  • Enter online
  • Hilly
  • Age 18 & over
  • Ultra runs

100K ultra runs near you

Select your location for 100K ultra marathons in your area.