| Season: | 1989–90 |
| Manager: | Alberto Bigon |
| League Result: | 1st |
| Cup2 Result: | Third round |
| Pattern B1: | _napoli8283h |
| Leftarm1: | 3da4df |
| Body1: | 5486be |
| Rightarm1: | 3da4df |
| Socks1: | 3da4df |
| Pattern La2: | _napoli8990a |
| Pattern B2: | _napoli8990a |
| Pattern Ra2: | _napoli8990a |
| Pattern La3: | _napoli8081a |
| Pattern B3: | _napoli8687a |
| Pattern Ra3: | _napoli8081a |
| Shorts3: | ff0000 |
| Socks3: | ff0000 |
| League Topscorer: | Maradona (16) |
| Season Topscorer: | Maradona (18) |
| Nextseason: | 1990–91 |
S.S.C. Napoli won their second ever Italian championship, thanks to a new club record in points scored over the course of the season. Diego Maradona scored 16 of the side's 57, whilst the contributions of other players such as Careca and Gianfranco Zola gave Napoli enough of an attacking edge to claim the title.
| Out | |||||||
|---|---|---|---|---|---|---|---|
| width=3% | Pos. | width=33% | Name | width=28% | To | width=36% | Type |
| DF | Avellino | ||||||
| MF | |||||||
| MF | Giovanni Di Rocco | Torres | loan | ||||
| Out | |||||||
|---|---|---|---|---|---|---|---|
| width=3% | Pos. | width=33% | Name | width=28% | To | width=36% | Type |
| DF | loan | ||||||
| FW | Pisa | ||||||
See main article: 1989–90 Serie A.
See main article: 1989–90 Coppa Italia. First roundSecond roundGroup phase-Group BSemifinals
See main article: 1989–90 UEFA Cup. Round of 32Round of 16Eightfinals