| Competition: | Serie B |
| Season: | 1989–90 |
| Winners: | Torino 2nd title |
| Promoted: | Pisa Cagliari Parma |
| Relegated: | Monza Licata Como Catanzaro |
| League Topscorer: | Andrea Silenzi (23 goals) |
| Matches: | 380 |
| Total Goals: | 674 |
| Prevseason: | 1988–89 |
| Nextseason: | 1990–91 |
The Serie B 1989–90 was the fifty-eighth tournament of this competition played in Italy since its creation.
Triestina, Reggiana, Cagliari and Foggia had been promoted from Serie C, while Torino, Pescara, Pisa and Como had been relegated from Serie A.
Monza relegated to Serie C1.