The 1990 Supercopa Libertadores was the third season of the Supercopa Libertadores, a club football tournament for past Copa Libertadores winners. The tournament was won by Olimpia, who beat Nacional 6–3 on aggregate in the final.
First round
The matches were played from 18 October to 8 November. Teams from the same nation could not be drawn against one another. Boca Juniors, as the title holders, entered the competition at the quarter-finals. ==Quarter-finals==
Quarter-finals
The matches were played from 14 to 21 November. ==Semi-finals==
Semi-finals
The matches were played from 28 November to 10 December. ==Final==