Cherry County is a county in the U.S. state of Nebraska. As of the 2020 United States Census, the population was 5,455. Its county seat is Valentine. The county was named for Lt. Samuel A. Cherry, an Army officer who was stationed at Fort Niobrara and was killed in South Dakota in 1881. Cherry County is in the Nebraska Sandhills. It is the state's largest county, at nearly 6,000 square miles, larger than the state of Connecticut.