Forty people die when ice covering the boating lake at Regent's Park, London, collapses.

The Regent's Park skating disaster occurred on 15 January 1867 when 40 people died after the ice broke on the lake in London's Regent's Park pitching about 200 people into icy water up to 12 ft (3.7 m) deep. Most were rescued by bystanders but 40 people died either from hypothermia or by drowning. The incident was considered at the time to be the worst weather-related accident in Britain. One of the consequences of the incident was that the lake bottom was raised and the overall depth of the lake reduced to a maximum depth of 4 ft (1.2 m), to help prevent adult drownings in the future.

Regent's Park is one of the Royal Parks of London. It occupies 410 acres (170 ha) in north-west Inner London, administratively split between the City of Westminster and the Borough of Camden. In addition to its large central parkland and ornamental lake, it contains various structures and organizations both public and private, generally on its periphery, including Regent's University and London Zoo.

London is the capital and largest city of both England and the United Kingdom, with a population of 8,945,309 in 2023. Its wider metropolitan area is the largest in Western Europe, with a population of 15.1 million. London stands on the River Thames in southeast England, at the head of a 50-mile (80 km) tidal estuary down to the North Sea, and has been a major settlement for nearly 2,000 years. Its ancient core and financial centre, the City of London, was founded by the Romans as Londinium and has retained its medieval boundaries. The City of Westminster, to the west of the City of London, has been the centuries-long host of the national government and parliament. London grew rapidly in the 19th century, becoming the world's largest city at the time. Since the 19th century the name "London" has referred to the metropolis around the City of London, historically split between the counties of Middlesex, Essex, Surrey, Kent and Hertfordshire, which since 1965 has largely comprised the administrative area of Greater London, governed by 33 local authorities and the Greater London Authority.