Leeds United Association Football Club, commonly referred to as simply Leeds United or informally Leeds, are an English professional football club based in Leeds, West Yorkshire. The club's home is the Elland Road stadium in Beeston, where they have played since their foundation in 1919. The club has competed at the top level of English football for the majority of its existence, following the disbanding of its predecessor Leeds City. However, Leeds competed in League One for the 2007–08 season; the first time the club dropped below the top two tiers of domestic football in England, following severe financial turmoil.

Under the management of Don Revie during the 1960s and 1970s, Leeds won a number of domestic and European trophies. After Revie's departure to manage the England team, Leeds were relegated to the Second Division in 1982, not returning to the top flight until 1990, when they were managed by Howard Wilkinson. Leeds were league champions two seasons later, in 1992.

The club's most common nicknames are "Leeds", "United" or "The Whites". Another nickname is "The Peacocks", though this is virtually obsolete. This term stems from the former name of the Elland Road, The Old Peacock Ground, which was in turn named after The Old Peacock pub opposite Elland Road's South Stand. .

Although the club name bears the "AFC" suffix, the current badge displays "LUFC". However, previous badges have included the official suffix in its entirety.

Pre-Leeds United

Leeds United's predecessor team Leeds City FC was formed in 1904, but was forcibly disbanded by The Football League in 1919 in response to allegations of illegal payments to players during the First World War. A new club, Leeds United, was formed and the club received an invitation to enter the Midland League from the league secretary, Mr. J Nicholson. Leeds United were voted into the Midland League on 31 October 1919, taking the place vacated by Leeds City Reserves. Yorkshire Amateurs, who occupied Elland Road, offered to make way for the new team under the management of former player Dick Ray. The chairman of Huddersfield Town, Mr. Hilton Crowther loaned Leeds United £ , to be repaid when Leeds United won promotion to Division One. He brought Barnsley's manager Arthur Fairclough to Leeds and on 26 February 1920, Dick Ray stepped down to become Fairclough's assistant.

1920-1959

On 31 May 1920, Leeds United were elected to the Football League.

Over the following few years, Leeds consolidated their position in the Second Division and in 1924 won the title and with it promotion to the First Division. However, they failed to establish themselves and were relegated in 1926-27. After being relegated Fairclough resigned which paved the way for Ray to return as manager. In the years up until the start of World War II Leeds were twice relegated, both times being instantly re-promoted the following season. On 5 March 1935 Ray resigned and he was replaced by Billy Hampson, who remained in charge for 12 years. In the 1946-47 season after the war, Leeds were relegated again with the worst league record in their history. After this season, Hampson resigned (he stayed with Leeds as their chief scout albeit for only 8 months) and was replaced in April 1947 by Willis Edwards.