The 1989–90 UEFA Cup was the 19th season of the UEFA Cup, the secondary club football competition organised by the Union of European Football Associations (UEFA).

The final was played over two legs at the Stadio Comunale Vittorio Pozzo, Turin, Italy, and at the Stadio Partenio, Avellino, Italy.

The competition was won by Juventus, who defeated fellow Italian team Fiorentina by an aggregate result of 3–1 to claim their second UEFA Cup title.

This was the first final between two Italian sides in the UEFA competitions history and the third between two clubs of the same country.

This was the fifth and final season in which all English clubs were banned from European football competitions A total of 65 teams from 31 UEFA member associations participated in the 1988–89 UEFA Cup.

The association ranking based on the UEFA country coefficients is used to determine the number of participating teams for each association: Due to the ongoing English ban, their first birth was allocated to association 9, gaining a third birth.

As two associations were tied for 10th place in the UEFA rankings, both of them qualified a third team for a preliminary round, whose winner would take the remaining English birth in the first round.

For the 1989–90 UEFA Cup, the associations are allocated places according to their 1988 UEFA country coefficients, which takes into account their performance in European competitions from 1983–84 to 1987–88.

Matches were scheduled for Tuesdays and Wednesdays, with each legs of both semifinals now being held over consecutive days.

The match was abandoned in the 104th minute with the score at 1–1 after Austria Wien's goalkeeper Franz Wohlfahrt was struck by an iron rod thrown from the home stand.

As a result, Ajax had to concede the match by default and were excluded from competing in European football for a year.

2–2 on aggregate; Rapid Wien won on away goals.

Red Star Belgrade won 3–1 on aggregate.

Žalgiris Vilnius won 2–1 on aggregate.

Red Star Belgrade won 5–1 on aggregate.