Fort Lee (formerly Fort Gregg-Adams from 2023 to 2025) is a United States Army post in Prince George County, Virginia and headquarters of the United States Army Combined Arms Support Command (CASCOM)/ Sustainment Center of Excellence (SCoE), the U.S. Army Quartermaster School, the U.S. Army Ordnance School, the U.S. Army Transportation School, the Army Sustainment University (ALU), Defense Contract Management Agency (DCMA), and the U.S. Defense Commissary Agency (DeCA).

Fort Lee also hosts two Army museums (the U.S. Army Quartermaster Museum and the U.S. Army Women's Museum), a Military Entrance Processing Command station, and the vocational training schools for culinary specialists in the U.S. Army and U.S. Navy. The equipment and other materiel associated with the Army's Ordnance Museum was moved to Fort Gregg-Adams in 2009 and 2010 for use by the United States Army Ordnance Training and Heritage Center.

For statistical purposes, the United States Census Bureau has defined Fort Lee as a census-designated place (CDP) with a population of 9,874 as of the 2020 census – nearly triple the size of the 2010 census count.

The installation was initially named Camp Lee (changed to Fort Lee in 1950) after Robert E. Lee, a Confederate general. It was one of the U.S. Army installations named for Confederate soldiers that the U.S. Naming Commission had recommended be renamed. On 8 August 2022, the commission proposed the name be changed to Fort Gregg-Adams, after Lieutenant General Arthur J. Gregg and Lieutenant Colonel Charity Adams Earley. On 6 October 2022, Secretary of Defense Lloyd Austin accepted the recommendation and directed the name change occur no later than 1 January 2024. On 5 January 2023, William A. LaPlante, US under-secretary of defense for acquisition and sustainment, directed the full implementation of the recommendations. On 27 April 2023, the post was redesignated Fort Gregg-Adams. It is the first U.S. military base to be named for African Americans. In June of 2025, the name was again changed to Ft. Lee, but this time to honor Buffalo Soldier Private Fitz Lee, a Spanish-American War veteran who, under enemy fire, rescued wounded soldiers in Cuba, earning him the Medal of Honor.

Just 18 days after a state of war with Germany was declared, the first Camp Lee was established as a state mobilization camp and later became a division training camp.

Camp Lee was the mobilization center for the 80th Division, the Blue Ridge Division. Because of significant common heritage in the past (Colonial Wars, Revolutionary War, and Civil War), residents of Pennsylvania, Virginia and West Virginia became the structure of the 80th Division. The 80th Division was organized in August 1917 at Camp Lee, Virginia. The units were made up mostly of men from the above three states. To symbolize the three aforementioned states, an insignia with three blue mountain peaks was adopted and included the latin motto vis montium (strength of the mountains). The 80th division was then shipped to France with 23,000 soldiers by June 8th of 1918. They went on to play a key role in the Second Battle of Somme and the Meuse Argonne offensive.

"Before long, Camp Lee became one of the largest 'cities' in Virginia. More than 60,000 Doughboys trained here prior to their departure for the Western Front and fighting in France and Germany. Included among the many facilities here was a large camp hospital situated on 58 acres of land. One of the more trying times for the hospital staff was when the worldwide influenza epidemic reached Camp Lee in the fall of 1918. An estimated 10,000 Soldiers were stricken by flu. Nearly 700 of them died during a couple of weeks."

In June 1917, building began and within sixty days some 14,000 men were on the installation. The post was home to the 155th Depot Brigade. The role of depot brigades was to receive recruits and draftees, then organize them and provide them with uniforms, equipment and initial military training. Depot brigades also received soldiers returning home at the end of the war and carried out their mustering out and discharges. When construction work ended, there were accommodations for 60,335 men.