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.

Nevada is a landlocked state in the Western region of the United States. It borders Oregon to the northwest, Idaho to the northeast, California to the west, Arizona to the southeast, and Utah to the east. Nevada is the 7th-most extensive, the 32nd-most populous, and the 9th-least densely populated of the U.S. states. Nearly three-quarters of Nevada's people live in Clark County, which contains the Las Vegas–Paradise metropolitan area, including three of the state's four largest incorporated cities. Nevada's capital is Carson City. Las Vegas is the largest city in the state.