Royal Windsor Triathlon Start your summer strong at one of the UK's most iconic multisport events on Sunday 13th June 2027. Take on the challenge by yourself or in a team. The day begins with an open water swim in the River Thames - keep an eye out for swans! Next, take on a thrilling road cycle through the historic town of Windsor, passing Windsor Castle and heading into the scenic countryside. You’ll finish with a memorable run into Windsor Great Park, along the iconic Long Walk, with the castle framing your final strides. Sign up - Standard entry Sign up - Standard relay entry Other running events How we help Manage Cookie Preferences