Royal Windsor Triathlon Presented by Sigma Sports June 2026

The Royal Windsor Triathlon begins in the River Thames and sends athletes past royal landmarks in Windsor, Berkshire, each June. It is a mass-participation triathlon with sprint, Olympic-distance, and relay options. The sprint race uses a 750-metre swim, 22-kilometre bike leg, and 5-kilometre run. The Olympic race doubles the swim to 1,500 metres, stretches the bike to 40 kilometres, and finishes with a 10-kilometre run. Around 3,000 to 3,500 competitors usually enter, including club racers, first-timers, relay teams, and experienced triathletes on the same morning. The swim is an out-and-back route on the Thames, starting near Queen Elizabeth Bridge and passing Baths Island. The bike course uses open roads through Windsor and the Berkshire countryside, with Windsor Castle on the route. The run moves into Windsor Great Park and along the Long Walk, where the castle remains in view. The race began in 1991 and is among the UK’s longest-running triathlons, with seven British Triathlon Federation “Event of the Year” awards. Its start lists have also included famous names from outside triathlon, such as Jonny Wilkinson, Tanni Grey-Thompson, Gareth Thomas, Jenson Button, and Princess Beatrice of York.