The UEFA Europa League (abbreviated as UEL), formerly the UEFA Cup, is an annual football club competition organised since 1971 by the Union of European Football Associations (UEFA) for eligible European football clubs. It is the second-tier competition of European club football, ranking below the UEFA Champions League and above the UEFA Europa Conference League. The UEFA Cup was the third-tier competition from 1971 to 1999 before the UEFA Cup Winners' Cup was discontinued, and it is still often referred to as the “C3” in reference of this. Clubs qualify for the competition based on their performance in their national leagues and cup competitions.

Introduced in 1971 as the UEFA Cup, it replaced the Inter-Cities Fairs Cup. In 1999, the UEFA Cup Winners' Cup was merged with the UEFA Cup and discontinued as a separate competition. From the 2004–05 season a group stage was added before the knockout phase. The competition has been known as the Europa League since the 2009–10 season, following a change in format. The 2009 re-branding included a merge with the UEFA Intertoto Cup, producing an enlarged competition format, with an expanded group stage and a change in qualifying criteria. The winner of the UEFA Europa League qualifies for the UEFA Super Cup and, since the 2014–15 season, qualifies for the following season's UEFA Champions League, entering at the group stage.

Spanish clubs have the highest number of victories (13 wins), followed by teams from England and Italy (9 wins each). The title has been won by 29 clubs, 14 of which have won it more than once. The most successful club in the competition is Sevilla, with six titles. Eintracht Frankfurt are the reigning champions, having beaten Rangers 5–4 on penalties in the 2022 final.

The UEFA Cup was preceded by the Inter-Cities Fairs Cup, which was a European football competition played between 1955 and 1971. The competition grew from 11 teams during the first edition (1955–58) to 64 teams by the last edition which was played in 1970–71, being abolished and replaced by the UEFA Cup, a new seasonal confederation competition which have a different regulation, format and disciplinary committee.