Best was born and raised in Belfast where, at the age of 15, he was discovered by a Manchester United scout. He joined United's youth academy, then signed a professional contract with them in 1963. He soon became a crowd favorite, with his flashy playing style and long-haired good looks earning him the nickname "the Fifth Beatle" and making him one of football's first international superstars. He helped United to several honors, including the European Cup in 1968, the same year he was named European Footballer of the Year.
Unfortunately, Best's playing career began to suffer as he battled with his alcoholism. He left United in 1974 and started a journey that saw him play for a number of different clubs, including the Los Angeles Aztecs (1976, 1977-78), Fulham (1976-77), Ft. Lauderdale Strikers (1978-79), Hibernian (1979-80), and the San Jose Earthquakes (1980-81). He last played for Tobermore United in the Northern Irish league, for whom he made a single appearance in 1984.
He also earned 37 caps for Northern Ireland between 1964 and 1977, but the side did not qualify for the World Cup during that time.