The 2027 TCS London Marathon has been confirmed as a historic two-day event, taking place from April 24-25, 2027. This unprecedented schedule was decided through a playful rock, paper, scissors contest between two former champions: Sebastian Sawe and Catherine Debrunner.

With a record 100,000 participants anticipated, the marathon will feature elite races split across both days. Sebastian Sawe, the defending men's champion known for breaking the sub-two-hour barrier in 2026, and Catherine Debrunner, a four-time London champion who set the women's wheelchair marathon record in 2023, engaged in a best-of-three contest to finalize the race dates.

• Saturday, April 24: Elite Men and Men's Wheelchair races
• Sunday, April 25: Elite Women's and Women's Wheelchair races

Debrunner's victory secured the traditional Sunday slot for the elite women's events, while the mass participation events will include a diverse mix of male, female, and non-binary runners across both days.

Hugh Brasher, CEO of London Marathon Events, commented on the significance of the upcoming marathon, stating, "The 2027 Double TCS London Marathon will be a momentous one-off event. The competition may not be quite so friendly when race weekend arrives!"

This unique format is expected to generate the largest fundraising moment in UK sporting history, with projections of over £150 million ($200 million) raised for charitable causes at the event.