| 1989 Thriftway ATP Championship | |
|---|---|
| Date | August 14–20 |
| Edition | 88th |
| Category | Grand Prix circuit |
| Draw | 64S / 32D |
| Prize money | $485,000 |
| Surface | Hard / outdoor |
| Location | Mason, Ohio, U.S. |
| Venue | Lindner Family Tennis Center |
| Champions | |
| Singles | |
 Brad Gilbert[1] | |
| Doubles | |
| Ken Flach / Robert Seguso[2] | |
The 1989 Thriftway ATP Championship, also known as the Cincinnati Open, was a men's tennis tournament played on outdoor hard courts at the Lindner Family Tennis Center in Mason, Ohio in the United States that was part of the 1989 Nabisco Grand Prix. The tournament was held from August 14 through August 20, 1989. Fifth-seeded Brad Gilbert won the singles title.
- ^ "1989 Cincinnati – Singles draw". Association of Tennis Professionals (ATP).
- ^ "1989 Cincinnati – Doubles draw". Association of Tennis Professionals (ATP).