Chelsea FC was founded in 1905 by Henry Augustus Mears. Home games are played at Stamford Bridge stadium, the original site Mears chose for the club. The team had mixed fortunes over the years, not winning a major trophy until the 1950s and moving up and down between divisions several times. The Blues improved their standing since the 1990s to become one of the most successful clubs in English football. They won English Premier League titles in 2004–05 and 2005–06, adding to their only previous league win, in 1954–55 (then in the Football League First Division), and making them the second English team to win consecutive championships since the founding of the Premier League in 1992. They took the European Cup Winners' Cup in 1971 and 1998 and the Union of European Football Associations (UEFA) Super Cup in 1998. Chelsea FC won the Football Association Challenge Cup (FA Cup) four times—in 1970, 1997, 2000, and 2007.

Despite Chelsea's roller-coaster history, an array of notable players have performed with the club. Top stars from the 1960s onward include Bobby Tambling, Jimmy Greaves, Terry Venables, John Hollins, Ray Wilkins, Gianfranco Zola, Frank Lampard, and Didier Drogba. On the downside, Chelsea fans include one of England's most notorious gangs of football hooligans, known as the Headhunters; they have been responsible for organized violence in the stands since the 1970s, usually consisting of assaults on fans of other teams.