| Competition: | Alpha Ethniki |
| Season: | 1990–91 |
| Winners: | Panathinaikos 16th Greek title |
| Relegated: | Ionikos Levadiakos PAS Giannina |
| Continentalcup1: | European Cup |
| Continentalcup1 Qualifiers: | Panathinaikos |
| Continentalcup2: | UEFA Cup |
| Continentalcup2 Qualifiers: | AEK Athens PAOK |
| Continentalcup3: | Cup Winners' Cup |
| Continentalcup3 Qualifiers: | Athinaikos |
| League Topscorer: | Dimitris Saravakos (23 goals) |
| Matches: | 306 |
| Total Goals: | 772 |
| Prevseason: | 1989–90 |
| Nextseason: | 1991–92 |
The 1990–91 Alpha Ethniki was the 55th season of the highest football league of Greece. The season began on 16 September 1990 and ended on 2 June 1991. Panathinaikos won their second consecutive and 16th Greek title.
The point system was: Win: 2 points - Draw: 1 point.
| Rank | Player | Club | Goals |
|---|---|---|---|
| 1 | Dimitris Saravakos | Panathinaikos | 23 |
| 2 |  Krzysztof Warzycha | Panathinaikos | 18 |
| 3 | Nikos Anastopoulos | Olympiacos | 16 |
| 4 | Giorgos Vaitsis | Panachaiki | 15 |
| 5 |  Daniel Batista | AEK Athens | 13 |
| 6 | Giorgos Skartados | PAOK | 12 |
| 7 | Aris Karasavvidis | Apollon Athens | 11 |
| Oleh Protasov | Olympiacos | ||
| 9 | Vangelis Kalogeropoulos | Ionikos | 10 |
| Stathis Pechlivanidis | Levadiakos | ||
| Yuri Savichev | Olympiacos |
