1881 U.S. National Championships (tennis)
| 1881 U.S. National Championships | |
|---|---|
 | |
| Date | August 31 – September 3 |
| Edition | 1st |
| Surface | Grass |
| Location | Newport, Rhode Island, United States |
| Venue | Newport Casino |
| Champions | |
| Singles | |
 Richard D. Sears | |
| Doubles | |
| Clarence Clark / Fred Taylor | |
The inaugural U.S. National Championship (now known as the US Open) was a tennis tournament that took place in August 1881 at the Newport Casino, Newport, Rhode Island. For the first and only time, only clubs that were members of the United States National Lawn Tennis Association were permitted to enter the tournament. A Men's Singles competition and a Men's Doubles competition were played, and Richard Sears became the first men's singles U.S. National Tennis Champion.
Finals
Singles
Richard Sears defeated 
William E. Glyn 6–0, 6–3, 6–2
Doubles
Clarence Clark / Fred Taylor defeated Arthur Newbold / Alexander Van Rensselaer, 6-5, 6-4, 6-5