The 1990–91 Scottish Premier Division season was won by Rangers, two points ahead of Aberdeen.

Rangers had seemed on course for a comfortable victory in the championship, but a loss of form around the time of manager Graeme Souness leaving the club allowed a surging Aberdeen to take the lead in the championship after 35 games.

[1] Rangers won a league deciding match against Aberdeen in the final game of the season at Ibrox.

[1] Mark Hateley scored twice in a 2–0 victory for Rangers, giving them their third successive league championship.

[1][2][3] Due to a league expansion from 10 to 12 teams, no clubs were relegated.