Kennewick is a city in Benton County in southeastern Washington. It is the most populous of the three cities collectively referred to as the Tri-Cities. Kennewick is located along the southwest bank of the Columbia River, opposite Pasco and just south of the confluence of the Columbia and Yakima rivers. As of the 2004 census estimates, the city had a total population of 60,118, making it the largest city in Benton County. Kennewick apartments for rent comparison page shows most up to date rent information on Kennewick apartments and houses. Rent information is obtained from multiple rental sources but we cannot guarantee their accuracy.