Central London is the innermost part of London, England. There is no official or commonly accepted definition of its area, but its characteristics are understood to include a high density built environment, high land values, an elevated daytime population and a concentration of regionally, nationally and internationally significant organisations and facilities. From time to time, and for a variety of purposes, a number of definitions have been used to define the scope of central London.

Road distances to London are traditionally measured from a central point at Charing Cross, which is marked by the statue of King Charles I at the junction of the Strand, Whitehall and Cockspur Street, just south of Trafalgar Square.

The London Plan includes a central activities zone policy area. This comprises the City of London, most of Westminster and the inner parts of Camden, Islington, Hackney, Tower Hamlets, Southwark, Lambeth and Kensington and Chelsea. It is described as "a unique cluster of vitally important activities including central government offices, headquarters and embassies, the largest concentration of London's financial and business services sector and the offices of trade, professional bodies, institutions, associations, communications, publishing, advertising and the media".

London ⁱ/ˈlʌndən/ is the capital city of England and the United Kingdom, the largest metropolitan area in the United Kingdom, and the largest urban zone in the European Union by most measures. Located on the River Thames, London has been a major settlement for two millennia, its history going back to its founding by the Romans, who named it Londinium. London's ancient core, the City of London, largely retains its square-mile mediaeval boundaries. Since at least the 19th century, the name London has also referred to the metropolis developed around this core. The bulk of this conurbation forms the London region and the Greater London administrative area, governed by the elected Mayor of London and the London Assembly.

London is a leading global city, with strengths in the arts, commerce, education, entertainment, fashion, finance, healthcare, media, professional services, research and development, tourism and transport all contributing to its prominence. It is the world's leading financial centre alongside New York City and has the fifth-largest city GDP in the world (and the largest in Europe). London has been described as a world cultural capital. It was the world's most visited city during 2011 and London Heathrow is the world's busiest airport by number of international passengers. London's 43 universities form the largest concentration of higher education in Europe. In 2012 London will become the first city to host the modern Summer Olympic Games three times.