Owyhee County is a county in the southwestern corner of the U.S. state of Idaho. As of the 2020 census, the population was 11,913. The county seat is Murphy, and its largest city is Homedale. In area it is the second-largest county in Idaho, behind Idaho County. Owyhee County is part of the Boise metropolitan area and contains slightly more than half of the Duck Valley Indian Reservation, which extends over the Nevada border, into Elko County.