The UEFA Cup was preceded by the
Inter-Cities Fairs Cup, which was a European
competition played between 1955 and 1971. The competition grew from 11 teams during the first cup (
1955–58) to 64 teams by the last cup which was played in
1970–71. It had become so important on the European football scene that in the end it was taken over by
UEFA and relaunched the following season as the UEFA Cup.
The UEFA Cup was first played in the 1971–72 season, with an all-English final of
Wolverhampton Wanderers against
Tottenham Hotspur, with Spurs taking the first honours. The title was retained by another English club,
Liverpool, in 1973, who defeated
Borussia Mönchengladbach in the final. Borussia would win the competition in 1975 and 1979, and reach the final again in 1980. Liverpool won the competition for the second time in 1976 after defeating
Club Brugge in the final.
During the 1980s,
IFK Göteborg (1982 and 1987) and
Real Madrid (1985 and 1986) won the competition twice each, with
Anderlecht reaching two consecutive finals, winning in 1983 and losing to Tottenham Hotspur in 1984. The year 1989 saw the commencement of the Italian clubs' domination, when
Stuttgart. The 1990s started with two all-Italian finals, and in 1992,
Torino lost the final to
Ajax on the
away goals rule.
Juventus won the competition for a third time in 1993 and
Internazionale kept the cup in Italy the following year. The year 1995 saw a third all-Italian final, with
Parma proving their consistency, after two consecutive Cup Winners' Cup finals. The only final with no Italians during that decade was in 1996. Internazionale reached the final the following two years, losing in 1997 to
Schalke 04 on penalties, and winning yet another all-Italian final in 1998, taking home the cup for the third time in only eight years. Parma won the cup in 1999, which ended the Italian club era.
Liverpool won the competition for the third time in 2001 and
Porto triumphed in the 2003 and 2011 tournaments, with the latter against Portuguese team
Braga. In 2004, the cup returned to Spain with
Valencia being victorious, and then
Sevilla succeeded on two consecutive occasions in 2006 and 2007, the latter in a final against fellow Spaniards
Espanyol. Either side of Sevilla's success, two Russian teams,
CSKA Moscow in 2005 and
Zenit Saint Petersburg in 2008, had their glory and yet another former Soviet club, Ukraine's
Shakhtar Donetsk, won in 2009.
Atlético Madrid would themselves win twice in three seasons, in 2010 and 2012, the latter in another all-Spanish final. In 2013,
Chelsea would become the first Champions League holders to win the UEFA Cup/Europa League the following year. In 2014,
Sevilla won their third cup in eight years after defeating
Benfica on penalties. Just one year later, in 2015, Sevilla won their fourth UEFA Cup/Europa League, becoming the most successful club in the competition.
The competition was traditionally open to the runners-up of domestic leagues, but the competition was merged with UEFA's previous second-tier European competition, the
UEFA Cup Winners' Cup, in 1999. Since then, the winners of domestic cup competitions have also entered the UEFA Cup. Further, clubs eliminated in the third qualifying round of the UEFA Champions League and the third-placed teams at the end of the group phase could go on to compete in the UEFA Cup. Winners of some selected domestic
League Cup competitions are also admitted.
Since the 2009–10 season, the competition has been known as the UEFA Europa League.
 At the same time, the
UEFA Intertoto Cup, UEFA's third-tier competition, was discontinued and merged into the new Europa League.