Ironman triathlons in the UK
An Ironman or full distance triathlon is one of the toughest event formats around and only do-able by the most committed athletes with both the physical and mental endurance to cross the finish line. Also called a 140.6 triathlon or full distance triathlon, these long-distance events involve a 2.4-mile swim (3.9km), a 112-mile bike ride (180km), and a 26.2-mile run (42.2km) - a total of 140.6 miles completed in an average of around 10-15 hours. Select your location for full distance triathlons in your area or scroll down to see major events coming up.
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Full distance triathlons in 2025/2026
Featured events are listed below - select a month/region or the map view to see all events.
- Sun 7 Jun 2026
- €300-€350
Chateau de Chantilly | Bastion Triathlon
Race through the beautiful grounds and surrounding area of the stunning Château de Chantilly in The Bastion Iron Triathlon XXL then celebrate with friends and family in the festival village.
- 3.8 km lake swimming
- 180.2 km road cycling + 1708 ft ascent
- 42.2 km road running
- Sat 8 Aug 2026
- £250-£270
ATW Odyssey Full Distance Triathlon
Complete your own Odyssey on a journey of self-discovery in the Cambridgeshire countryside featuring a swim in the River Ouse, a scenic ride and a run around the beautiful town of St Neots.
- 3800 m river swimming
- 180 km road cycling + 3320 ft ascent
- 42.2 km road running
Ironman triathlons near you
Select your location for Ironman and 140.6 triathlons in your area.