A worldwide television audience of around 750 million people watch the wedding of Charles, Prince of Wales, and Lady Diana Spencer at St Paul's Cathedral in London.

The wedding of Prince Charles and Lady Diana Spencer took place on Wednesday, 29 July 1981, at St Paul's Cathedral in London, United Kingdom. The groom was the heir apparent to the British throne, and the bride was a member of the Spencer family.

St Paul's Cathedral, formally the Cathedral Church of St Paul the Apostle, is an Anglican cathedral in London, England, the seat of the Bishop of London. The cathedral serves as the mother church of the Diocese of London in the Church of England. It is on Ludgate Hill at the highest point of the City of London. Its dedication in honour of Paul the Apostle dates back to the original cathedral church on this site, founded in AD 604. The high-domed present structure, which was completed in 1710, is a Grade I listed building that was designed in the English Baroque style by Sir Christopher Wren. The cathedral's reconstruction was part of a major rebuilding programme initiated in the aftermath of the Great Fire of London. The earlier Gothic cathedral, largely destroyed in the Great Fire, was a central focus for medieval and early modern London, including Paul's walk and St Paul's Churchyard, being the site of St Paul's Cross.

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.