Kirkland is a city in King County, Washington, United States. It is a suburb of Seattle located on the Eastside. As of April 1, 2005, the city had an estimated population of 45,740, making Kirkland the eighth largest city in King County and the eighteenth largest city in the State. Kirkland apartments for rent comparison page shows most up to date rent information on Kirkland apartments and houses. Rent information is obtained from multiple rental sources but we cannot guarantee their accuracy.