George Best was born on May 22, 1946 in Belfast, Northern Ireland. At the age of 15 Best travelled to Manchester and was subsequently given a trial and signed up by United's chief scout Joe Armstrong. His first time moving to the club, Best quickly became homesick and stayed for only two days before going back home to Northern Ireland. He returned to Manchester and spent two years as an amateur, as English clubs were not allowed to take Northern Irish players on as apprentices. He was given a job as an errand boy on the Manchester Ship Canal, allowing him to train with the club twice a week.

Best made his first-division debut two years later, in 1963. He was an immediate sensation, scoring acrobatic goals and helping United to a league title in his second season. He led the club to another league championship during the 1966–67 season.

In 1968 United faced Benfica in the European Cup Final at Wembley. The game went into extra-time, and Best went on a mazy run and beat goalkeeper José Henrique with a dummy, before rolling the ball into the net; two further goals from Brian Kidd and Bobby Charlton settled the tie at 4–1.The victory, making United the first English European champions was not only the pinnacle of Best's career, but arguably Manchester United's greatest achievement, considering the Munich air disaster had wiped out most of the Busby Babes just ten years previously. Best also won the Ballon d'Or in 1968 after receiving more votes than Bobby Charlton, Dragan Džajić and Franz Beckenbauer. This meant that he had won the three major honours in club football at the age of just 22.

Best scored a total of 178 goals in his 466 career games with United.

In international football, Best was capped 37 times for Northern Ireland between 1964 and 1977. A combination of the team's performance and his lack of fitness in 1982 meant that he never played in the finals of a major tournament.

"George Best was one of the most talented players of all time and probably the best footballer who never made it to a major world final."

— 1974 World Cup winning West Germany captain Franz Beckenbauer.

During his early years at Old Trafford, Best was a shy teenager who passed his free time in snooker halls. However, he later became known for his long hair, good looks and extravagant celebrity lifestyle, and appeared on Top of the Pops in 1965. Called the “Fifth Beatle”, like them, Best was a colossal celebrity. His fame transcended the football world - Best was the first of many footballers to become a regular subject of the British tabloids.

He opened a nightclub called Slack Alice on Bootle Street in Manchester in 1973 and owned restaurants in the city including Oscars, on the site of the old Waldorf Hotel. He also owned fashion boutiques, in partnership with Manchester City player Mike Summerbee.

Although the football pitch was his arena, Best was essentially a pop star—young, stylish, strikingly beautiful, possessed of a creative confidence that bordered on arrogance, and worshipped by young men and women alike. Like The Beatles and The Rolling Stones, he epitomised the first, sudden, dynamic emergence of a postwar youth culture that, for better or worse, would help define the rest of the century. Long before Beckham, he was Britain's first footballer as popular icon.

— Sean O'Hagan in The Guardian on Best’s celebrity status in the 1960s

This status also helped foster a drinking problem that would prove to be his undoing. After a bitter departure from United in 1974, he played for numerous lesser teams in Britain, Spain, Australia, and the United States until 1983. His drinking continued to affect his play, however, and he became as well known for his squandered talent as for his undeniable brilliance.

Although conscious of his problems, he made light of them and was known for his intelligence and wit on the subject during periods of sobriety: "I spent a lot of money on booze, birds and fast cars – the rest I just squandered". After football, he spent some time as a football analyst, but his financial and health problems continued into his retirement.

Best underwent a liver transplant in 2002 but ultimately was unable to overcome his alcoholism, and he died from a series of transplant-related infections that his compromised immune system could not combat.