The UEFA Champions League is a seasonal football competition established in 1955. Prior to the 1992–93 season, the tournament was named the European Cup. The UEFA Champions League is open to the league champions of all UEFA (Union of European Football Associations) member associations (except Liechtenstein, which has no league competition), as well as to the clubs finishing from second to fourth position in the strongest leagues. Originally, only the champions of their respective national league and the defending champions of the competition were allowed to participate. However, this was changed in 1997 to allow the runners-up of the stronger leagues to compete as well, and again in 1999 when third and fourth-placed teams of the said leagues also became eligible. In the Champions League era, the defending champions of the competition did not automatically qualify until the rules were changed in 2005 to allow title holders Liverpool to enter the competition.

Teams that have won the UEFA Champions League three consecutive times, or five times overall, receive a multiple-winner badge. Six teams have earned this privilege: Real Madrid, Ajax, Bayern Munich, Milan, Liverpool, and Barcelona. Until 2009, clubs that had earned that badge were allowed to keep the European Champion Clubs' Cup and a new one was commissioned; since 2009, the winning team each year has received a full-size replica of the trophy, while the original is retained by UEFA.

A total of 22 clubs have won the Champions League/European Cup. Real Madrid hold the record for the most victories, having won the competition fourteen times, including the inaugural edition. They have also won the competition the most consecutive times, with five straight titles from 1956 to 1960. Juventus have been runners-up the most times, losing seven finals. Atlético Madrid is the only team to reach three finals without having won the trophy while Reims and Valencia have finished as runners-up twice without winning. Spain has provided the most champions, with nineteen wins from two clubs. England have produced fourteen winners from five clubs and Italy have produced twelve winners from three clubs. English teams were banned from the competition for five years following the Heysel disaster in 1985. The current champions are Real Madrid, who beat Liverpool 1–0 in the 2022 final for a record-extending fourteenth title.
Which club has won the most number of UEFA Champions League?
Real Madrid has won 14 of UEFA Champions League titles, make it the club that has won the most number of the tile, among all European clubs.