| 1991 US Open | |
|---|---|
| Date | August 26 – September 8 |
| Edition | 111th |
| Category | Grand Slam (ITF) |
| Surface | Hardcourt |
| Location | New York City, New York, United States |
| Champions | |
| Men's singles | |
 Stefan Edberg | |
| Women's singles | |
 Monica Seles | |
| Men's doubles | |
 John Fitzgerald / Anders Järryd | |
| Women's doubles | |
 Pam Shriver /  Natasha Zvereva | |
| Mixed doubles | |
 Manon Bollegraf / Tom Nijssen | |
| Boys' singles | |
 Leander Paes | |
| Girls' singles | |
 Karina Habšudová | |
| Boys' doubles | |
 Karim Alami /  John-Laffnie de Jager | |
| Girls' doubles | |
| Kristin Godridge / Nicole Pratt | |
The 1991 US Open was a tennis tournament played on outdoor hard courts at the USTA National Tennis Center in New York City in New York in the United States. It was the 111th edition of the US Open and was held from August 26 to September 8, 1991.