| Competition: | Tunisian National Championship |
| Season: | 1990–91 |
| Winners: | Espérance de Tunis |
| Relegated: | Sfax Railways Sports AS Oued Ellil |
| Continentalcup1: | Cup of Champions |
| Continentalcup1 Qualifiers: | Espérance de Tunis Club Africain |
| Continentalcup2: | Cup Winners' Cup |
| Continentalcup2 Qualifiers: | Étoile du Sahel |
| Continentalcup3: | CAF Cup |
| Continentalcup3 Qualifiers: | CA Bizertin |
| League Topscorer: | Fethi Chehaibi "Bargou" (15 goals) |
| Biggest Home Win: | CA 4–0 USM EST 4–0 OB |
| Biggest Away Win: | CSS 0–4 CAB |
| Highest Scoring: | ASM 4–2 JSK CAB 4–2 ESS COT 4–2 ASM USM 4–2 COT CA 3–3 CSS ST 3–3 AS Ouued Ellil |
| Matches: | 182 |
| Total Goals: | 413 |
| Prevseason: | 1989–90 |
| Nextseason: | 1991−92 |
The 1990–91 Tunisian National Championship season was the 65th season of top-tier football in Tunisia.