Sevier County is a county in Utah, United States. As of the 2020 United States Census, the population was 21,522. Its county seat and largest city is Richfield.

The Black Hawk War, or Black Hawk's War, is the name of the estimated 150 battles, skirmishes, raids, and military engagements taking place from 1865 to 1872, primarily between Mormon settlers in Sanpete County, Sevier County and other parts of central and southern Utah, and members of 16 Ute, Southern Paiute, Apache and Navajo tribes, led by a local Ute war chief, Antonga Black Hawk. The conflict resulted in the abandonment of some settlements and hindered Mormon expansion in the region.