Fort Lewis is a United States military facility located 9.1 miles (14.6 km) south-southwest of Tacoma, Washington, under the jurisdiction of the United States Army Joint Base Garrison, Joint Base Lewis–McChord. It was merged with the United States Air Force's McChord Air Force Base on February 1, 2010 into a Joint Base as a result of Base Realignment and Closure Commission recommendations of 2005.

Joint Base Lewis-McChord is a training and mobilization center for all services and is the only Army power-projection base west of the Rocky Mountains. Its geographic location provides rapid access to the deep water ports of Tacoma, Olympia and Seattle for deploying equipment. Units can be deployed from McChord Field, and individuals and small groups can also use nearby Sea-Tac Airport. The strategic location of the base provides Air Force units with the ability to conduct combat and humanitarian airlift with the C-17 Globemaster III.