| 1991 PBA season | |
|---|---|
| Duration | February 17 – December 15, 1991 |
| Number of teams | 8 |
| TV partner(s) | Vintage Sports (PTV) |
| 1991 PBA Draft | |
| Top draft pick | Alejandro Araneta |
| Picked by | Alaska Milkmen |
| Season MVP | Alvin Patrimonio (Purefoods TJ Hotdogs) |
| First Conference champions | Ginebra San Miguel |
| First Conference runners-up | Shell Rimula X |
| All-Filipino Conference champions | Purefoods TJ Hotdogs |
| All-Filipino Conference runners-up | Diet Sarsi Sizzlers |
| Third Conference champions | Alaska Milkmen |
| Third Conference runners-up | Ginebra San Miguel |
The 1991 PBA season was the 17th season of the Philippine Basketball Association (PBA).