The 79th Pennsylvania Volunteer Infantry (also known as the "Lancaster Rifles") was an infantry regiment that served in the Union Army during the American Civil War.

The 79th Pennsylvania Infantry was organized at Lancaster, Pennsylvania and mustered in for a three-year enlistment on September 19, 1861, under the command of Colonel Henry Augustus Hambright.

The regiment was attached to Negley's 4th Brigade, McCook's Command, at Nolin, to November 1861.

Negley's Independent Brigade, Army of the Ohio, to August 1862.

28th Brigade, 3rd Division, Army of the Ohio, to September 1862.

28th Brigade, 3rd Division, I Corps, Army of the Ohio, to November 1862.

3rd Brigade, 1st Division, Centre, Army of the Cumberland, to January 1863.

3rd Brigade, 1st Division, XIV Corps, Army of the Cumberland, to April 1863.

Ordered to Columbia, Tenn., and guard Nashville & Decatur Railroad until May.

Ordered to Nashville, thence march to Louisville, Ky., in pursuit of Bragg August 21-September 26.

Guard Louisville & Nashville Railroad at Mitchellsville November 9-December 7.

Passage of Cumberland Mountains and Tennessee River, and Chickamauga Campaign August 16-September 22.

Davis Cross Roads or Dug Gap September 11.

Operations on line of Pumpkin Vine Creek and battles about Dallas, New Hope Church and Allatoona Hills May 25-June 5.

Ruff's Station, Smyrna Camp Ground, July 4.