The 4th Pennsylvania Cavalry Regiment was a cavalry regiment of the Union Army during the American Civil War.

The regiment was formed in late 1861, in Philadelphia, Harrisburg, and Pittsburgh for a 3-year service.

It was mustered into Federal service at the Soldier's Home near Washington, D.C. By March 1 only six companies were fully mounted, and one partially mounted.

Taken from Pennsylvania in the Civil War[1] Provost duty at Washington, D.C., till May 10, 1862.

Joined McDowell at Fredericksburg May, 1862, and scouting on the Rappahannock till June 14.

Moved to the Virginia Peninsula, arriving at White House June 24.

Gaines' Mill, Cold Harbor, June 27.

Rear guard to Army Potomac June 29.

Duty near Hartwood Church till December.

Scout to Catlett's Station and Brentsville December 21–23 (Detachment).

Expedition to Richard's and Ellis' Fords, Rappahannock River, December 29–30.

Operations at Rappahannock Bridge and Grove Church February 5–7.

Chancellorsville Campaign, Stoneman's Raid, April 29-May 8.

Stevensburg, Brandy Station and Beverly Ford June 9.

Warrenton or White Sulphur Springs October 12–13.

New Hope Church and Catlett's Station November 27.

(Cos. "A," "F" at Bull Run Bridge November, 1863, to January 20, 1864.)

At Camp Stoneman till May 12, and Joined Army Potomac May 19.)

Ground Squirrel Church and Yellow Tavern May 11.

White House or St. Peter's Church June 21.

Black Creek or Tunstall Station June 21.

Demonstration on north side of the James July 27–29.

Demonstration north of the James at Deep Bottom August 13–20.

Dinwiddie Road near Ream's Station August 23.

Reconnaissance to Poplar Springs Church September 13.

Boydton Plank Road, Hatcher's Run, October 27–28.

Dabney's Mills, Hatcher's Run, February 5–7.

Lewis Farm near Gravelly Run March 29 (Co. "C").

Paine's Cross Roads and Amelia Springs April 5.