Spokane County is a county located in the state of Washington. It is named after the Spokane Indian tribe. As of the 2007 Washington Census estimation, the population was 451,200, making it the fourth most populous county in Washington state. The county seat is at Spokane, the county's largest city, and the second largest city in Washington state to Seattle. Spokane County apartments for rent comparison page shows most up to date rent information on Spokane County apartments and houses. Rent information is obtained from multiple rental sources but we cannot guarantee their accuracy.