| Competition: | NSL First Division |
| Season: | 1990 |
| Winners: | Mamelodi Sundowns |
| Relegated: | Pilkington United Brothers Bush Bucks |
| Matches: | 306 |
| Total Goals: | 778 |
| Prevseason: | 1989 |
| Nextseason: | 1991 |
The 1991 National Soccer League First Division was the sixth edition of the NSL First Division in South Africa. It was won by Mamelodi Sundowns.[1] [2]