The predecessor of Leeds United Football Club is widely considered to be Leeds City FC, which was founded in 1904. However, following the First World War, financial irregularities within the club led to its expulsion from the English Football League. Left without their team, supporters established Leeds United in 1919.
Leeds United joined the Football League in 1920 and made its debut in the Second Division that August. After four seasons, the club earned promotion to the First Division in 1924, remaining there for three years. By the end of the 1920s, Leeds returned to the top flight and finished fifth in the league in 1929. Following the Second World War, the club was relegated once again and spent the next thirteen years in the Second Division.
In 1961, former Leeds winger Don Revie was appointed manager, beginning the most successful era in the club's history. Revie built his team around experienced players such as Jack Charlton and Billy Bremner, while introducing talented youngsters including Peter Lorimer and Norman Hunter. Under his leadership, Leeds won promotion to the First Division in 1964 and finished runners-up the following season. That achievement qualified the club for the Inter-Cities Fairs Cup, which Leeds won in the 1967–68 season by defeating Hungary's Ferencváros in the final. During the same campaign, Leeds also claimed their first League Cup, defeating Arsenal 1–0 at Wembley. The 1968–69 season became the finest in the club's history as Leeds won their first English league title, losing only two matches and setting a then-record total of 67 points.
In 1971, Leeds won the Inter-Cities Fairs Cup for the second time.
The following year, which marked the centenary of the FA Cup, Leeds captured the famous trophy for the only time in club history, defeating Arsenal 1–0 in the final.
In 1974, Jimmy Armfield guided Leeds to the 1975 European Cup Final. The match, played in Paris, ended in a 2–0 defeat to Bayern Munich and became notorious for crowd disturbances. After that defeat, Leeds did not compete in European competitions for four years.
During the following decade, former Leeds players Eddie Gray and Billy Bremner unsuccessfully attempted to restore the club to the top of English football. A revival began in 1988 with the appointment of Howard Wilkinson. Leeds secured promotion back to the First Division at the end of the 1989–90 season. Wilkinson strengthened the squad with signings including Gordon Strachan, Lee Chapman, Gary McAllister, Eric Cantona, and Vinnie Jones. Leeds finished fourth in the 1990–91 season before winning the First Division title in 1991–92, finishing four points ahead of Manchester United. This made Leeds the final champions of the old First Division before the formation of the Premier League in 1992. However, the club struggled in its first Premier League campaign, finishing seventeenth, before recording consecutive fifth-place finishes over the next two seasons.
In 1996, Leeds reached the League Cup Final for the first time in many years but lost 3–0 to Aston Villa at Wembley. Soon afterward, Howard Wilkinson left the club and was replaced by George Graham, whose tenure proved brief as he joined Tottenham Hotspur in September 1998. His assistant, David O'Leary, then took charge. Under O'Leary, Leeds finished fourth in the Premier League in 1998–99 and third in 1999–2000, qualifying for the UEFA Champions League. Ahead of the campaign, the club strengthened its squad with players such as Mark Viduka, Olivier Dacourt, Dominic Matteo, and Rio Ferdinand.
Leeds faced a daunting Champions League group in the 2000–01 season alongside Barcelona, AC Milan, and Beşiktaş. Despite a heavy 4–0 defeat away to Barcelona, Leeds defeated Milan and Beşiktaş, drew at home with Barcelona, earned a draw in Turkey, and held Milan away to progress from the group. They then defeated Deportivo La Coruña 6–2 on aggregate in the quarter-finals before losing 3–0 on aggregate to Valencia in the semi-finals. A fourth-place finish in the Premier League denied Leeds another Champions League campaign. Hoping to return, the club invested heavily in players including Robbie Fowler and Seth Johnson, but only managed fifth place in the 2001–02 season. By then, Leeds had spent approximately £100 million on transfers while recouping only £66 million from player sales, and by 2003 the club's total debt had reached around £80 million.
The financial crisis forced Leeds to sell many of its leading players, including Alan Smith, Harry Kewell, Jonathan Woodgate, Seth Johnson, and Lee Bowyer. The club also sold Elland Road and its training ground. After eleven consecutive seasons in England's top division, Leeds was relegated to the second tier, where it finished only 14th in the 2004–05 campaign. The following season, the club reached the promotion play-offs but lost 3–0 to Watford in the final. Matters worsened in 2007 when Leeds finished bottom of the Championship and, for the first time in its history, was relegated to League One, the third tier of English football.
Leeds began the 2007–08 season with a 15-point deduction after entering administration and due to financial issues connected with the club's ownership under Ken Bates. Despite the penalty, the team finished fifth and qualified for the promotion play-offs, only to lose 1–0 to Doncaster Rovers in the final.
In 2008–09, Leeds finished fourth but was eliminated by Millwall in the play-off semi-finals. The following season, the club secured automatic promotion by finishing second in League One.
From the 2010–11 season onward, Leeds competed in the Championship but did not reach the promotion play-offs again until the 2018–19 campaign, when they were eliminated in the semi-finals by Derby County. A year later, the club finally secured automatic promotion by winning the Championship title.
Leeds spent three consecutive seasons in the Premier League before finishing second from bottom in the 2022–23 campaign and being relegated back to the Championship.
In the 2025–26 Championship season, Leeds United secured promotion once again and will return to the Premier League for the 2026–27 season.