The 1990–91 season of the Moroccan Throne Cup was the 35th edition of the competition.
Kawkab Marrakech won the cup, beating KAC Kénitra 2–1 in the final, played at the Prince Moulay Abdellah Stadium in Rabat. Kawkab Marrakech won the competition for the fifth time in their history.
The final took place between the two winning semi-finalists, Kawkab Marrakech and KAC Kénitra, at the Prince Moulay Abdellah Stadium in Rabat.