Seal - Yavapai County 3D print model

Yavapai County was one of the four original Arizona counties created by the 1st Arizona Territorial Legislature. The county territory was defined as being east of longitude 113° 20' and north of the Gila River.[3] Soon thereafter, the counties of Apache, Coconino, Maricopa, and Navajo were carved from the original Yavapai County. Yavapai County's present boundaries were established in 1891.

The county is named after the Yavapai people, who were the principal inhabitants at the time the United States annexed the area.

County level law enforcement services have been provided by Yavapai County Sheriff's Office since 1864.