1981 ATP Championship
| 1981 Cincinnati Open | |
|---|---|
| Date | August 17–23 |
| Edition | 80th |
| Draw | 64S / 32D |
| Prize money | $200,000 |
| Surface | Hard / outdoor |
| Location | Mason, Ohio, U.S. |
| Venue | Lindner Family Tennis Center |
| Champions | |
| Singles | |
 John McEnroe | |
| Doubles | |
| John McEnroe / Ferdi Taygan | |
The 1981 Cincinnati Open (also known as the 1981 ATP Championships for sponsorship reasons) was a 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 1981 Volvo Grand Prix. The tournament was held from August 17 through August 23, 1981.
Finals
Singles
John McEnroe defeated 
Chris Lewis 6–3, 6–4
- It was McEnroe's 8th singles title of the year and the 32nd of his career.
Doubles
John McEnroe / Ferdi Taygan defeated Bob Lutz / Stan Smith 7–6, 6–3
