1990–91 FIBA European Cup Winner's Cup

The 1990–91 FIBA European Cup Winner's Cup was the twenty-fifth edition of FIBA's competition for European basketball national cup champions, running from 25 September 1990 to 26 March 1991. It was contested by 19 teams, two less than the previous edition.

PAOK defeated CAI Zaragoza in a final held in Geneva, winning its first European title ever. It was the second Greek club that win the Cup Winner's Cup after AEK from the distant 1968.