Fort DeRussy was an American Civil War-era fortification constructed in 1861 on a hilltop along the west bank of Rock Creek within Washington, D.C., as part of the Defenses of Washington.

It was a trapezoidal earthwork with a perimeter of 190 yards, and places for 13 guns.

There were also supporting rifle pits, and abatis in the Rock Creek streambed.

Today, the grounds of the fort are administered by the U.S. National Park Service as part of Rock Creek Park in the northern portion of the District of Columbia.

[6] The site, heavily wooded, is easily reached by a trail from the west bank of the creek north of Military Road, so-called because it connected the ring of defensive installations around the capital.