Annandale is located in Northern Virginia, nestled within the Piedmont geographic region—a plateau area situated between the Atlantic coastal plain and the main Appalachian Mountains. It sits approximately 13 miles southwest of Washington, D.C.
The physical geography is defined by a lush, heavily wooded suburban landscape characterized by mature deciduous trees (such as oak, maple, and hickory). The community is bisected by several important stream valleys, most notably Accotink Creek to the west and Holmes Run to the east. These waterways are preserved by extensive park authorities, offering a network of green spaces, trails, and natural habitats amidst an otherwise densely developed commercial and residential environment.