| 1998 US Open | |
|---|---|
| Date | August 31 – September 13 | 
| Edition | 118th | 
| Category | Grand Slam (ITF) | 
| Surface | Hardcourt | 
| Location | New York City, New York, United States | 
| Champions | |
| Men's singles | |
| Women's singles | |
| Men's doubles | |
| Women's doubles | |
| Mixed doubles | |
| Boys' singles | |
| Girls' singles | |
| Boys' doubles | |
| Girls' doubles | |
The 1998 US Open was a tennis tournament played on outdoor hardcourts at the USTA National Tennis Center in New York City in New York in the United States. It was the 118th edition of the US Open and was held from August 31 through September 13, 1998.
Seniors
Men's singles
 Patrick Rafter defeated 
 Mark Philippoussis, 6–3, 3–6, 6–2, 6–0
- • It was Rafter's 2nd and last career Grand Slam singles title and his 2nd at the US Open.
 
Women's singles
 Lindsay Davenport defeated 
 Martina Hingis, 6–3, 7–5
- • It was Davenport's 1st career Grand Slam singles title and her 1st and only at the US Open.
 
Men's doubles
 Sandon Stolle / 
 Cyril Suk defeated 
 Mark Knowles / 
 Daniel Nestor, 4–6, 7–6, 6–2
- • It was Stolle's 1st and only career Grand Slam doubles title.
 - • It was Suk's 1st and only career Grand Slam doubles title.
 
Women's doubles
 Martina Hingis / 
 Jana Novotná defeated 
 Lindsay Davenport / 
 Natasha Zvereva 6–3, 6–3
- It was Hingis' 10th career Grand Slam title and her 2nd and last US Open title. It was Novotná's 17th and last career Grand Slam title and her 4th US Open title. With this victory Hingis completed the second doubles Grand Slam in a calendar year in the Open Era, with Martina Navratilova and Pam Shriver having completed the first in 1984.
 
Mixed doubles
 Serena Williams / 
 Max Mirnyi defeated 
 Lisa Raymond / 
 Patrick Galbraith 6–2, 6–2
- • It was Williams's 2nd career Grand Slam mixed doubles title and her 1st at the US Open.
 - • It was Mirnyi's 2nd career Grand Slam mixed doubles title and his 1st at the US Open.
 
Juniors
Boys' singles
 David Nalbandian defeated 
 Roger Federer 6–3, 7–5
Girls' singles
 Jelena Dokić defeated 
 Katarina Srebotnik 6–4, 6–2
Boys' doubles
 K. J. Hippensteel / 
 David Martin defeated 
 Andy Ram / 
 Lovro Zovko 6–7, 7–6, 6–2
Girls' doubles
 Kim Clijsters[1] / 
 Eva Dyrberg defeated 
 Jelena Dokić / 
 Evie Dominikovic 7–6, 6–4