The 82nd Pennsylvania Volunteer Infantry was an infantry regiment that served in the Union Army during the American Civil War.
It was designated the 31st Pennsylvania Volunteer Infantry until after the Battle of Seven Pines but changed to avoid confusion with the 2nd Pennsylvania Reserve Regiment, which was renumbered.
The 82nd Pennsylvania Infantry was organized at Philadelphia, Pennsylvania for a three-year enlistment in August 1861 and mustered in under the command of Colonel David H. Williams.
The regiment was attached to Graham's Brigade, Buell's (Couch's) Division, Army of the Potomac, October 1861 to March 1862.
2nd Brigade, 1st Division, IV Corps, Army of the Potomac, to July 1862.
3rd Brigade, 1st Division, IV Corps, to September 1862.
3rd Brigade, 3rd Division, VI Corps, Army of the Potomac, to October 1862.
1st Brigade, 3rd Division, VI Corps, to January 1864.
4th Brigade, 1st Division, VI Corps, Army of the Potomac, to July 1864.
The 82nd Pennsylvania Infantry mustered out of service on July 13, 1865.
Duty in Maryland and along the Potomac River until November 1.
Operations about Deep Run Ravine June 6–13.
Moved to Johnson's Island, Lake Erie, January 6, 1864, and duty there guarding prisoners until May 6.
Moved to Washington, D.C., then joined the Army of the Potomac in the field.
Repulse of Early's attack on Washington July 11–12.
Sheridan's Shenandoah Valley Campaign August to December.
Dabney's Mills, Hatcher's Run, February 5–7, 1865.