Arlington National Cemetery in Arlington County, Virginia, is a military cemetery (United States National Cemetery) in the United States of America, established during the American Civil War on the grounds of Arlington House (Arlington House, The Robert E. Lee Memorial), formerly the estate of the family of Confederate (Confederate States of America) general Robert E. Lees wife Mary Anna (Custis) Lee (Mary Anna Custis Lee), a descendant of Martha Washington. The cemetery is situated directly across the Potomac River from the Lincoln Memorial in Washington, D.C., and near The Pentagon. It is served by the Arlington Cemetery (Arlington Cemetery (Washington Metro)) station on the Blue Line of the Washington Metro system.

In an area of convert624acrekm2, veterans and military casualties from each of the nations wars are interred in the cemetery, ranging from the American Civil War through to the military actions in Afghanistan (War in Afghanistan (2001-present)) and Iraq (Iraq War). Pre-Civil War dead were reinterred after 1900.

Arlington National Cemetery and United States Soldiers and Airmens Home National Cemetery are administered by the Department of the Army (United States Department of the Army). The other national cemeteries are administered by the Department of Veterans Affairs (United States Department of Veterans Affairs) or by the National Park Service. Arlington House (Custis-Lee Mansion) and its grounds are administered by the National Park Service as a memorial to Lee.