1991 Currie Cup Rural D

The 1991 Currie Cup Rural D was the fifth division of the Currie Cup competition, the premier domestic rugby union competition in South Africa. This was the 53rd season since the competition started in 1889.

Changes between 1990 and 1991 seasons

 * The 1990 season was the last edition of the Santam Bank Trophy. Instead, these teams were included in a Currie Cup Rural Division, which had a four-team Division C and a five-team Division D.
 * ,, , and  moved to the 1991 Currie Cup Rural D.

Changes between 1991 and 1992 seasons

 * Following the merger of all rugby governing bodies in South Africa, and  were dissolved.  Currie Cup Rural D was reduced to three teams for 1992.
 * The Currie Cup Rural D was renamed Currie Cup Rural B for 1992.

Competition
There were five participating teams in the 1991 Currie Cup Rural D competition. These teams played each other twice over the course of the season, once at home and once away. Teams received two points for a win and one points for a draw. The winner of the Rural D competition played off against the winner of the Rural C competition for the Bankfin Trophy.

Final
The winner of the Rural D competition played off against the winner of the Rural C competition for the Bankfin Trophy.

Relegation play-off
In the play-off match, beat  to clinch a spot in the 1992 Currie Cup Rural A, while  would play in the 1992 Currie Cup Rural B.