Ormsby County was a county of Nevada from 1861 until 1969. It contained Carson City, the county seat and later state capital, founded two years earlier. It was named after Major William M. Ormsby , one of the original settlers of Carson City, killed in 1860.

In 1969, the county was dissolved and the independent city of Carson City took over all municipal services. Another state capital is also not in any county: Richmond, Virginia.

See also: List of extinct U.S. counties, List of Nevada counties