1890 U.S. National Championships (tennis)

1890 U.S. National Championships
DateAugust 18–27 (M)
June 10–13 (W)
Edition10th
CategoryGrand Slam
SurfaceGrass
LocationNewport, R.I., United States (M)
Philadelphia, PA, United States (W)
Champions
Men's singles
Oliver Campbell
Women's singles
Ellen Roosevelt
Men's doubles
Valentine Hall / Oliver Campbell
Women's doubles
Grace Roosevelt / Ellen Roosevelt

The 1890 U.S. National Championships (now known as the US Open) was a tennis tournament that took place from June to August of 1890. The women's singles and doubles competitions were held from June 10 to June 13 on the outdoor grass courts at the Philadelphia Cricket Club in Philadelphia, Pennsylvania. The men's singles and doubles competitions were held from August 18 to August 27 on the outdoor grass courts at the Newport Casino in Newport, Rhode Island. It was the 10th U.S. National Championships and the second Grand Slam tournament of the year.