The 1990–91 Northern Counties East Football League season was the 9th in the history of Northern Counties East Football League, a football competition in England. Division Two was disbanded at the end of the season. Most of the Division Two clubs were promoted to Division One.
| Competition: | Northern Counties East Football League Premier Division |
| Season: | 1990–91 |
| Winners: | Guiseley |
| Promoted: | Guiseley |
| Matches: | 240 |
| Prevseason: | 1989–90 |
| Nextseason: | 1991–92 |
The Premier Division featured 12 clubs which competed in the previous season, along with four new clubs.
| Competition: | Northern Counties East Football League Division One |
| Season: | 1990–91 |
| Winners: | Sheffield |
| Promoted: | Sheffield Liversedge Eccleshill United Glasshoughton Welfare |
| Matches: | 156 |
| Prevseason: | 1989–90 |
| Nextseason: | 1991–92 |
Changes made before start of season:
BSC Parkgate changed name to RES Parkgate.Collingham, Woolley Miners Welfare and Frecheville Community Association all left the league.
| Competition: | Northern Counties East Football League Division Two |
| Season: | 1990–91 |
| Winners: | Hall Road Rangers |
| Promoted: | Hall Road Rangers Worsbrough Bridge Miners Welfare Bradley Rangers Yorkshire Amateur Tadcaster Albion Stocksbridge Park Steels Immingham Town Brodsworth Welfare |
| Matches: | 156 |
| Total Goals: | 487 |
| Prevseason: | 1989–90 |
Division One featured ten clubs which competed in the previous season, along with three new clubs, relegated from Division One: