Federal Way is a city in King County, Washington, United States. Federal Way is located between Seattle and Tacoma. Its northwestern boundary is Puget Sound. It is bordered by Des Moines and Kent on the north, Auburn as well as Lakeland North and Lakeland South in unincorporated King County on the east, Milton on the south, and Tacoma as well as Fife Heights and Dash Point in unincorporated Pierce County on the southwest. The population was 89,306 at the 2010 Census. Federal Way is currently the 9th largest city in Washington State and the 5th largest in King County, according to the Census Bureau's 2014 population estimate.