It has been confirmed that the London Marathon 2027 will be a two-day event and will be held on Saturday 24 and Sunday 25 April 2027. This one-off change could see 100,000 participants over both days and represents a significant opportunity for charities that use this type of event to raise funds.
You can find out more from https://www.londonmarathonevents.co.uk/london-marathon/2027-tcs-london-marathon-double-faqs.