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.
| 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 | |
Seniors
editMen's singles
edit Stefan Edberg defeated Jim Courier 6–2, 6–4, 6–0
- It was Edberg's 5th career Grand Slam title and his 1st US Open title.
Women's singles
edit Monica Seles defeated Martina Navratilova 7–6(7–1), 6–1
- It was Seles' 4th career Grand Slam title and her 1st US Open title.
Men's doubles
edit John Fitzgerald / Anders Järryd defeated Scott Davis / David Pate 6–3, 3–6, 6–3, 6–3
- It was Fitzgerald's 9th and last career Grand Slam title and his 3rd US Open title. It was Järryd's 8th and last career Grand Slam title and his 2nd US Open title.
Women's doubles
edit Pam Shriver / Natasha Zvereva defeated Jana Novotná / Larisa Savchenko 6–4, 4–6, 7–6(7–5)
- It was Shriver's 22nd and last career Grand Slam title and her 5th US Open title. It was Zvereva's 4th career Grand Slam title and her 1st US Open title.
Mixed doubles
edit Manon Bollegraf / Tom Nijssen defeated 
Arantxa Sánchez Vicario / Emilio Sánchez 6–2, 7–6(7–2)
- It was Bollegraf's 2nd career Grand Slam title and her 1st US Open title. It was Nijssen's 2nd and last career Grand Slam title and his only US Open title.
Juniors
editBoys' singles
edit Leander Paes defeated Karim Alami 6–4, 6–4
Girls' singles
edit Karina Habšudová defeated Anne Mall 6–1, 6–3
Boys' doubles
edit Karim Alami / John-Laffnie de Jager defeated Michael Joyce / Vince Spadea 6–4, 6–7, 6–1
Girls' doubles
edit Kristin Godridge / Nicole Pratt defeated Åsa Carlsson / 
Cătălina Cristea 7–6, 7–5