Chelsea Football Club is a professional football club based in London, England, that competes in the Premier League, the highest tier of English football. The club has won eight League titles, eight FA Cups, five League Cups, four FA Community Shields, one UEFA Europa League, one UEFA Super Cup, one UEFA Cup Winners' Cup, and one UEFA Champions League.
Founded in 1905, the club's home ground since then has been Stamford Bridge. Chelsea won its only First Division title in 1955, but saw limited success in various cup competitions until 2003, when the club was purchased by Russian billionaire Roman Abramovich. Chelsea then saw heavy investment, and have since won eighteen honours under Abramovich.
José Mourinho is the club's most successful manager in terms of the number of major honours won, and his title-winning team set an English record for points between 2004 and 2005. Chelsea have traditionally wore a royal blue kit with white socks, and the club's crest features a ceremonial lion rampant regardant holding a staff. The club have rivalries with neighbouring clubs Fulham, Arsenal, and Tottenham Hotspur.
In terms of club value, Chelsea are the seventh most valuable football club in the world, worth £1.54 billion ($2.06 billion), and are the eighth highest-earning football club in the world, with earnings of over €428 million in the 2017–18 season. Based on attendance figures, the club have the sixth-largest fanbase in England.