Burnley Football Club (/ˈbɜːrnli/) is a professional football club based in Burnley, Lancashire, England. The team compete in the Premier League, the top tier of the English football league system. Founded in 1882, Burnley were one of the first to become professional (in 1883) and subsequently put pressure on the Football Association to permit payments to players. They entered the FA Cup for the first time in 1885–86 and were one of the 12 founder members of the Football League in 1888–89, the world's first league football competition.

Burnley are one of only five sides to have won all four professional divisions of English football, and have twice been crowned champions of England, in 1920–21 and 1959–60. They have won the FA Cup once, in 1913–14, and have won the FA Charity Shield twice, in 1960 and 1973. The team have also finished as runners-up in both the First Division and FA Cup on two occasions. During the 1920–21 campaign, Burnley embarked on a 30-match unbeaten league run, setting an English record. From the 1950s until the 1970s, under chairman Bob Lord, Burnley were renowned for their youth policy and scouting system, and were one of the first to set up a purpose-built training ground. The majority of the team that won the 1959–60 league title had progressed through the club's youth academy. At the time, Burnley—with a population of 80,000—became one of the smallest towns to produce an English first-tier champion.

The team have played home games at Turf Moor since 1883, after they had moved from their original premises at Calder Vale. Nicknamed "The Clarets", the club colours of claret and blue were adopted in 1910. The club's current emblem is based on the town of Burnley's coat of arms. The side have a long-standing rivalry with nearby club Blackburn Rovers, with whom they contest the East Lancashire Derby. Burnley's record appearance holder is Jerry Dawson, who made 569 appearances in a 22-year playing spell with the team, and their record goalscorer is George Beel with 188 goals.

The club was founded on 18 May 1882 by members of rugby team Burnley Rovers, who voted for a shift to association football as the sport was gaining prominence in the area. The suffix "Rovers" was dropped a few days later. The side won their first silverware in 1883: the Dr Dean's Cup, a knockout competition between amateur clubs in the Burnley area. By the end of the year, the club turned professional and signed many Scottish players, who were regarded as the best footballers by the Burnley committee. As a result, Burnley refused to join the Football Association (FA) and its FA Cup because the association barred professional players. In 1884, Burnley led a group of 35 other clubs in the formation of the breakaway British Football Association (BFA) to challenge the FA's supremacy. The FA changed its rule in 1885, allowing professionalism, and Burnley made their first appearance in the FA Cup in 1885–86. In October 1886, Burnley's Turf Moor became the first professional ground to be visited by a member of the royal family, when Prince Albert Victor attended a friendly between Burnley and Bolton Wanderers. The club was among the twelve founders of the Football League in 1888–89, the world's first league football competition, and one of the six based in Lancashire. In the second match, William Tait became the first player in history to score a league hat-trick, with his three goals against Bolton Wanderers securing Burnley's inaugural win in the competition. In 1889–90, they claimed their first Lancashire Cup, after beating local rivals Blackburn Rovers in the final.

Burnley were relegated to the Second Division for the first time in 1896–97. The team won the division the next season; they lost only two of thirty matches before gaining promotion through a four-team play-off series called test matches, although the last game against First Division club Stoke was controversial. It finished 0–0 as both needed only a draw for a top flight place, and it was later named "[t]he match without a shot at goal". Burnley were relegated again in 1899–1900 and became embroiled in controversy when goalkeeper Jack Hillman attempted to bribe opponents Nottingham Forest during the final match of the season, which resulted in his suspension for the entire following campaign. It is possibly the earliest recorded case of match fixing in football. The side continued to play in the Second Division and even finished in bottom place in 1902–03—but were re-elected—as the club got into financial difficulties.

Harry Windle was named chairman in 1909, after which the club's finances turned around. In 1910, the Burnley directors changed the club's colours from green to claret and blue, and appointed John Haworth as the team's new manager. In 1912–13, the side won promotion to the first tier, and the following season, Burnley won their first major honour, beating Liverpool in the 1914 FA Cup final. Bert Freeman scored the only goal as Burnley became the first club to defeat five top tier sides in one cup season. Tommy Boyle became the first captain to receive the trophy from a reigning monarch, King George V. The team finished second to West Bromwich Albion in 1919–20, before winning their first ever First Division championship in 1920–21. Burnley lost the opening three games but went unbeaten in the following 30 league matches, setting an English record. Nine seasons later, the team were relegated to the Second Division. They struggled in the second tier and avoided a further relegation in 1931–32 by two points. The years through to the outbreak of the Second World War were characterised by mid-table league finishes.

In 1946–47, the first season of post-war League football, Burnley won promotion to the First Division and reached the FA Cup final, in which they were defeated by Charlton Athletic after extra time. The team's defence was nicknamed "The Iron Curtain", since they conceded only 29 goals in 42 league matches. Alan Brown, captain of Burnley's 1946–47 side, was appointed the club's manager in 1954, with Bob Lord becoming chairman a year later. The club became one of the most progressive around under their tenures. Burnley were one of the first to set up a purpose-built training ground, at Gawthorpe, and they became renowned for their youth policy and scouting system, which yielded many young talents. In 1958, former Burnley player Harry Potts was appointed manager. His squad mainly revolved around the duo of captain Jimmy Adamson and Jimmy McIlroy, the team's playmaker. Potts often employed the then unfashionable 4–4–2 formation and he implemented a Total Football playing style.

Burnley clinched a second First Division title in 1959–60. They had not topped the table until the last match was played out. The squad cost only £13,000 (equivalent to £380,000 in 2023) in transfer fees—£8,000 on McIlroy in 1950 and £5,000 on left-back Alex Elder in 1959. The other Burnley players had progressed through the club's youth academy. With 80,000 inhabitants, the town of Burnley became one of the smallest to have an English first tier champion. The side travelled to the United States after the season ended to represent England in the International Soccer League, the first modern international American soccer tournament. The following season, Burnley played in European competition for the first time in the 1960–61 European Cup. They defeated former finalists Reims in the first round, but went out against Hamburger SV in the quarter-finals. The team finished the 1961–62 First Division as runners-up to newcomers Ipswich Town after winning only one of the last ten matches, and had a run to the 1962 FA Cup final but lost against Tottenham Hotspur. Adamson was named FWA Footballer of the Year, however, with McIlroy as runner-up.