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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Map view100K ultra runs in 2025/2026
Featured events are listed below - select a month/region or the map view to see all events.
- Sat 25 Apr 2026
- £90.50
North Wales 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 + 8000 ft ascent
- Sat 20 Jun 2026
- £165
Race to the King | 100K Non-Stop
The full circuit takes in both the Coastal and Castle loops for a magnificent tour of the stunning South Downs. Steeped in history and uniquely varied, the 100K offers a course truly fit for royalty.
- 100 km trail running + 1510 m ascent
- Sat 11 - Sun 12 Jul 2026
- £85-£255
Race to the Stones
Conquer Britain's oldest trail, the ancient Ridgeway, as you race towards the 5000-year-old Avebury Standing Stones.
- 50K ultra run 2
- 100K ultra run 3
100K ultra runs near you
Select your location for 100K ultra marathons in your area.