Lieutenant Colonel Sir John Frederick Dame Johnston, GCVO, MC (24 August 1922 – 10 September 2006) was a British Army officer and courtier. He joined the Royal Household in 1964, serving as Assistant Comptroller and then Comptroller of the Lord Chamberlain's Office. Sometimes known as "Stopwatch Johnny", he was one of the Queen's most popular courtiers. His duties included co-ordinating the weddings of Charles, Prince of Wales and Lady Diana Spencer at St Paul's Cathedral in 1981 and of Prince Andrew and Sarah Ferguson at Westminster Abbey in 1986, and the funeral of The Duchess of Windsor at St George's Chapel, Windsor, also in 1986.