| 1899 U.S. National Championships | |
|---|---|
| Date | August 14–21 (M) June 21–24 (W) |
| Edition | 19th |
| Category | Grand Slam |
| Surface | Grass |
| Location | Newport, R.I., United States (M) Philadelphia, PA, United States (W) |
| Champions | |
| Men's singles | |
 Malcolm Whitman[1] | |
| Women's singles | |
| Marion Jones[1] | |
| Men's doubles | |
| Holcombe Ward / Dwight Davis[1] | |
| Women's doubles | |
| Jane Craven / Myrtle McAteer[1] | |
| Mixed doubles | |
| Elizabeth Rastall / Albert Hoskins[1] | |
List of champions of the 1899 U.S. National Championships tennis tournament (now known as the US Open). The men's tournament was held from August 14 to August 21 on the outdoor grass courts at the Newport Casino in Newport, Rhode Island. The women's tournament was held from June 21 to June 24 on the outdoor grass courts at the Philadelphia Cricket Club in Philadelphia, Pennsylvania. It was the 19th U.S. National Championships and the second Grand Slam tournament of the year.