Ephrata is a city in and the county seat of Grant County, Washington, United States. Its population was 8,477 at the 2020 census.

Grant County is a county located in the U.S. state of Washington. As of the 2020 census, the population was 99,123. The county seat is Ephrata, and the largest city is Moses Lake. The county was formed out of Douglas County in February 1909 and is named for U.S. President Ulysses S. Grant.