Box Butte County is a county in the U.S. state of Nebraska. As of the 2020 United States Census, the population was 10,842. Its county seat is Alliance. The county was formed in 1886; it took its name from a large box-shaped butte north of Alliance.

Alliance is a city and the county seat of Box Butte County, in the western part of the state of Nebraska, in the Great Plains region of the United States. Its population was 8,151 at the 2020 census.