Named for Mexican–American War hero brevet Brigadier General Sylvester Churchill, the county was formed in 1861.

Churchill County comprises the Fallon, NV Micropolitan Statistical Area.

In the 19th century there were several attempts to eliminate Churchill County because of its small population, but Assemblyman Lemuel Allen stopped it on all occasions including convincing the Governor to veto an 1875 bill after it had been passed by both houses.

The Eagle Salt Works Railroad ran for 13.5 miles (21.7 km), primarily on the original Central Pacific grade from Luva (2 miles (3.2 km) east of Fernley) to Eagle Salt Works.

The Central Pacific portion of the nation's first transcontinental railroad ran through Churchill County, although a portion of the original route has been shifted for a new route south of Wadsworth in favor of Fernley.

The terrain of Churchill County consists of rugged mountainous ridges, dotted with lakes and ponds.

[3] The county's east and west sides are higher than the intermediate valley; its highest point around the county periphery is a ridge on the lower east boundary line, at 9,380 ft (2,860 m) ASL.

[3] [3] As of the 2000 United States Census,[35] the county had 23,982 people, 8,912 households, and 6,461 families.

[40] Lying on the boundary between the northwest urban areas of Nevada and the conservative Mormon Great Basin, Churchill County has more in common with the latter region, being overwhelmingly Republican.

The last time Churchill County voted for a Democratic presidential candidate was when it supported Franklin D. Roosevelt against Wendell Willkie in 1940.