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.

This event gives participants the opportunity to take in a runnable, beautiful route which follows the North Walian coastline between Prestatyn and Bangor.
  • Sat 26 Apr
  • £84.50
Prestatyn, Clwyd, UK

North Wales 50K & 100K | 100K

This event gives participants the opportunity to take in a runnable, beautiful route which follows the North Walian coastline between Prestatyn and Bangor.

  • 100 km trail running
Great challenges need great settings, and up to 2,000 adventurers will take on the Isle of Wight stunning coastal path – all out to push themselves further.
  • Sat 3 May
  • £199
Ventnor, Isle of Wight, UK

Isle of Wight Ultra Challenge | Full Continuous

Great challenges need great settings, and up to 2,000 adventurers will take on the Isle of Wight stunning coastal path – all out to push themselves further.

  • 106 km multi terrain running + 1800 m ascent
The full 106km circumnavigation of the Isle of Wight, in daylight hours. Overnight at Cowes for a well-earned rest on this wonderful exploration of the coastal routes around the island.
  • Sat 3 - Sun 4 May
  • £199
Ventnor, Isle of Wight, UK

Isle of Wight Ultra Challenge | Full 2 Day Daylight

The full 106km circumnavigation of the Isle of Wight, in daylight hours. Overnight at Cowes for a well-earned rest on this wonderful exploration of the coastal routes around the island.

  • 106 km multi terrain running + 1960 m ascent
A demanding challenge, taking on 100km along the UNESCO World Heritage Jurassic Coast, starting from Corfe Castle on a fully-supported challenge visiting the highlights of the region.
  • Sat 17 - Sun 18 May
  • £199
Wareham, Dorset, UK

Jurassic Coast Ultra Challenge | Full 100km continuous

A demanding challenge, taking on 100km along the UNESCO World Heritage Jurassic Coast, starting from Corfe Castle on a fully-supported challenge visiting the highlights of the region.

  • 100 km trail running + 2300 m ascent
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
  • £199
Wareham, Dorset, UK

Jurassic Coast Ultra Challenge | Full 100km over 2 days

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!

  • 100 km trail running + 2300 m ascent
Leafy Richmond to sunny Brighton – over the North Downs and the South Downs, with some wonderful Surrey and Sussex countryside in between, fully supported all the way with a huge celebratory finish!
  • Sat 24 May
  • £199
Richmond, UK

London 2 Brighton Ultra Challenge | Full 100km Continuous

Leafy Richmond to sunny Brighton – over the North Downs and the South Downs, with some wonderful Surrey and Sussex countryside in between, fully supported all the way with a huge celebratory finish!

  • 100 km trail running + 1500 m ascent
Leafy Richmond to sunny Brighton, over the North and South Downs, with some wonderful Surrey and Sussex countryside - all in daylight hours and with a good nights' sleep mid-way!
  • Sat 24 - Sun 25 May
  • £199
Richmond, UK

London 2 Brighton Ultra Challenge | Full 100km over 2 days

Leafy Richmond to sunny Brighton, over the North and South Downs, with some wonderful Surrey and Sussex countryside - all in daylight hours and with a good nights' sleep mid-way!

  • 100 km trail running + 1500 m ascent
100km of trails, high passes, stunning scenery, Ambleside, the magnificent Lake Windermere, nature reserves, forests and over 2,500m of ascent. Fully supported all the way with a celebratory finale!
  • Sun 1 - Sun 8 Jun
  • £199
Kendal, Cumbria, UK

Lake District Ultra Challenge | Full 100km continuous

100km of trails, high passes, stunning scenery, Ambleside, the magnificent Lake Windermere, nature reserves, forests and over 2,500m of ascent. Fully supported all the way with a celebratory finale!

  • 100 km trail running + 2500 m ascent
100km of trails, high passes, stunning scenery, Ambleside, the magnificent Lake Windermere, nature reserves, forests and over 2,500m of ascent. Fully supported with a good night's sleep mid-way.
  • Sat 7 - Sun 8 Jun
  • £199
Kendal, Cumbria, UK

Lake District Ultra Challenge | Full 100km over 2 days

100km of trails, high passes, stunning scenery, Ambleside, the magnificent Lake Windermere, nature reserves, forests and over 2,500m of ascent. Fully supported with a good night's sleep mid-way.

  • 100 km trail running + 2500 m ascent
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
Head into the rolling green hills of the Cotswolds with leg-testing climbs and breathtaking views on your 100km mission, with stops every 12-13km and a halfway break in Wotton, you're fully supported.
  • Sat 21 - Sun 22 Jun
  • £199
Cirencester, Gloucestershire, UK

Cotswold Way Ultra Challenge | Full 100km continuous

Head into the rolling green hills of the Cotswolds with leg-testing climbs and breathtaking views on your 100km mission, with stops every 12-13km and a halfway break in Wotton, you're fully supported.

  • 100 km trail running + 2250 m ascent
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  • Sat 21 - Sun 22 Jun
  • £199
Cirencester, Gloucestershire, UK

Cotswold Way Ultra Challenge | Full 100km over 2 days

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  • 100 km trail running + 2250 m ascent
Take on the full 100km in a figure-of-eight route through the north and south of the Peak District with stops every 12-13km and whatever support you need to get you to the finish line celebration!
  • Sat 28 - Sun 29 Jun
  • £199
Bakewell, Derbyshire, UK

Peak District Ultra Challenge | Full 100km continuous

Take on the full 100km in a figure-of-eight route through the north and south of the Peak District with stops every 12-13km and whatever support you need to get you to the finish line celebration!

  • 100 km trail running + 2150 m ascent
Take on the full 100km in a figure-of-eight route through the north and south of the Peak District in daylight with a good night's rest and full support to get you to the finish line celebration!
  • Sat 28 - Sun 29 Jun
  • £199
Bakewell, Derbyshire, UK

Peak District Ultra Challenge | Full 100km over 2 days

Take on the full 100km in a figure-of-eight route through the north and south of the Peak District in daylight with a good night's rest and full support to get you to the finish line celebration!

  • 100 km trail running + 2150 m ascent
Take on the full 100K ultramarathon in one go. Fully supported through day and night on an incredibly scenic and historic route to finish at the 5000-year-old Avebury standing stones.
  • Sat 12 Jul
  • £180-£190
Watlington, Oxfordshire, UK

Race to the Stones | 100K Non-stop

Take on the full 100K ultramarathon in one go. Fully supported through day and night on an incredibly scenic and historic route to finish at the 5000-year-old Avebury standing stones.

  • 100 km trail running + 3704 ft ascent
Take on the full 100K Race to the Stones ultramarathon with an overnight stop at the all-inclusive Basecamp, meaning a good nights' sleep in between the 50K stints.
  • Sat 12 Jul
  • £260-£270
Watlington, Oxfordshire, UK

Race to the Stones | 100K Two Days with camping

Take on the full 100K Race to the Stones ultramarathon with an overnight stop at the all-inclusive Basecamp, meaning a good nights' sleep in between the 50K stints.

  • 100 km trail running + 3704 ft ascent
Take on the full Race to the Stones 100K ultramarathon over two days, making your own arrangements for overnight accommodation at the halfway point (ideal if you'd prefer not to camp).
  • Sat 12 Jul
  • £170-£180
Watlington, Oxfordshire, UK

Race to the Stones | 100K Two Days no camping

Take on the full Race to the Stones 100K ultramarathon over two days, making your own arrangements for overnight accommodation at the halfway point (ideal if you'd prefer not to camp).

  • 100 km trail running + 3704 ft ascent
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
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
  • £199
Swansea, West Glamorgan, UK

Gower Peninsula Ultra Challenge | Full Continuous 100K

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.

  • 100 km multi terrain running
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
  • £199
Swansea, West Glamorgan, UK

Gower Peninsula Ultra Challenge | Full 2 Day Daylight 100K

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.

  • 100 km multi terrain running
The full distance option of the South Coast Challenge from sunny Eastbourne, over the magnificent Seven Sisters, onto Cuckmere Haven and over the South Downs all the way to historic Arundel.
  • Sat 6 - Sun 7 Sep
  • £199
Polegate, East Sussex, UK

South Coast Ultra Challenge | Full 100km continuous

The full distance option of the South Coast Challenge from sunny Eastbourne, over the magnificent Seven Sisters, onto Cuckmere Haven and over the South Downs all the way to historic Arundel.

  • 100 km trail running + 2100 m ascent
The full distance option of the South Coast Challenge over 2 days with 57km on day 1 and 43km on day 2, meaning you experience the route in daylight with the chance to sleep overnight.
  • Sat 6 - Sun 7 Sep
  • £199
Polegate, East Sussex, UK

South Coast Ultra Challenge | Full 100km over 2 days

The full distance option of the South Coast Challenge over 2 days with 57km on day 1 and 43km on day 2, meaning you experience the route in daylight with the chance to sleep overnight.

  • 100 km trail running + 2100 m ascent
The full, non-stop option of the Thames Path Challenge from leafy South West London following the river to Hampton Court, Runnymede to finish at Henley-on-Thames for a celebratory finish and BBQ.
  • Sat 13 - Sun 14 Sep
  • £199
London, UK

Thames Path Ultra Challenge | Full 100km Continuous

The full, non-stop option of the Thames Path Challenge from leafy South West London following the river to Hampton Court, Runnymede to finish at Henley-on-Thames for a celebratory finish and BBQ.

  • 100 km trail running + 350 m ascent
The full distance option of the Thames Path Challenge over 2 days with 50km on day 1 and 50km on day 2, meaning you experience the route in daylight with the chance to sleep overnight.
  • Sat 13 - Sun 14 Sep
  • £199
London, UK

Thames Path Ultra Challenge | Full 100km over 2 days

The full distance option of the Thames Path Challenge over 2 days with 50km on day 1 and 50km on day 2, meaning you experience the route in daylight with the chance to sleep overnight.

  • 100 km trail running + 350 m ascent
  • Sat 7 Jun
  • £109
Castle Douglas, Dumfries and Galloway, UK

Ultra Scotland 50

Take on 50 historic miles across the beautiful Southern Upland Way - one of the greatest trails in the UK. Ultrarunners will tackle several ascents, pass through forests, valleys and by lochs.

  • 56 miles trail running + 2447 m ascent

100K ultra runs near you

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