Eureka County is a county in the U.S. state of Nevada. As of the 2020 census, the population was 1,855, making it the second-least populous county in Nevada. Its county seat is Eureka.

Eureka is an unincorporated town and census-designated place in and the county seat of Eureka County, Nevada, United States. With a population of 414 as of the 2020 United States census, it is the second-largest community in Eureka County. Attractions include the Eureka Opera House, Raine’s Market and Wildlife Museum, the Jackson House Hotel, and the Eureka Sentinel Museum.