TCS London Marathon to run over two days in 2027

The TCS London Marathon will expand to a two-day format for its 2027 edition, held on Saturday 24 and Sunday 25 April, accommodating 100,000 participants across both days. The change, dubbed 'the Double,' is a one-off response to record demand, with 1.33 million people entering the ballot for 2027. Organisers project the expanded event could raise over £150 million for charity, surpassing the £90 million raised in 2026, along with an estimated £400 million in social and economic benefit to the UK.