On 24 February 1981 it was officially announced that Lady Diana was to marry The Prince of Wales. As neighbours at Sandringham until 1975, their families had known each other for many years, and Lady Diana and the The Prince had met again when he was invited to a weekend at Althorp in November 1977.
 
They were married at St Paul's Cathedral in London on 29 July 1981, in a ceremony which drew a global television and radio audience estimated at around 1,000 million people, and hundreds of thousands of people lining the route from Buckingham Palace to the Cathedral. The wedding reception was at Buckingham Palace.
 
The marriage was solemnised by the Archbishop of Canterbury Dr Runcie, together with the Dean of St Paul's; clergy from other denominations read prayers. Music included the hymns 'Christ is made the sure foundation', 'I vow to thee my country', the anthem 'I was glad' (by Sir Hubert Parry), a specially composed anthem 'Let the people praise thee' by Professor Mathias, and Handel's 'Let the bright seraphim' performed by Dame Kiri te Kanawa. The lesson was read by the Speaker of the House of Commons, Mr George Thomas (the late Lord Tonypandy).

The Princess was the first Englishwoman to marry an heir to the throne for 300 years (when Lady Anne Hyde married the future James II from whom the Princess was descended). The bride wore a silk taffeta dress with a 25-foot train designed by the Emanuels, her veil was held in place by the Spencer family diamond tiara, and she carried a bouquet of gardenias, lilies-of-the-valley, white freesia, golden roses, white orchids and stephanotis. She was attended by five bridesmaids including Princess Margaret's daughter Lady Sarah Armstrong-Jones (now Lady Sarah Chatto); Prince Andrew (now The Duke of York) and Prince Edward were The Prince of Wales's supporters (a Royal custom instead of a best man).