"3rd Metropolitan Guard") was an infantry regiment in the Union Army during the American Civil War.

The regiment was attached to Abercrombie's Division, Defenses of Washington, D.C., to November 1862.

3rd Brigade, 3rd Division, XIX Corps, Department of the Gulf, to March 1863.

Left New York for Washington, D, C., October 24, 1862, then moved to New Orleans, Louisiana, November.

Moved to Baton Rouge, Louisiana, March 7 (3 companies).

Moved to Baton Rouge, Louisiana, and duty there until September.

Monett's Ferry, Cane River Crossing, April 23.

Moved to New Orleans, then to Fort Monroe, Virginia, and Washington, D.C., July 1–13.

Detached with the brigade as supply train guard for the army August 14 to October 27.

Duty near Middletown and Newtown until December, and at Stephenson's Depot and Winchester until April 1865.