The 18th Pennsylvania Cavalry Regiment was a cavalry regiment of the Union Army during the American Civil War. The regiment was present for 50 battles, beginning with the Battle of Hanover in Pennsylvania on June 30, 1863, and ending with a skirmish at Rude's Hill in Virginia during March 1865. A majority of its fighting was in Virginia, although its first major battle was in Pennsylvania's Gettysburg campaign. It was consolidated with the 22nd Pennsylvania Cavalry Regiment on June 24, 1865, to form the 3rd Provisional Pennsylvania Cavalry Regiment.

The Battle of Hanover took place on June 30, 1863, in Hanover in southwestern York County, Pennsylvania, as part of the Gettysburg Campaign of the American Civil War.