The Partisan Ranger Act was passed on April 21, 1862, by the Confederate Congress. It was intended as a stimulus for recruitment of irregulars for service into the Confederate Army during the American Civil War. The Confederate leadership, like the Union leadership, later opposed the use of unconventional warfare out of fear the lack of discipline among rival guerrilla groups could spiral out of control. On February 17, 1864, the law was repealed after pressure from General Robert E. Lee and other Confederate regulars.

Only two partisan Ranger groups were exempt and allowed to continue to operate: Mosby's Raiders and McNeill's Rangers.

Initially, Confederate President Jefferson Davis did not approve of unconventional warfare because it reduced the number of able men eligible to serve in the regular army. However, after conventional Confederate forces were driven out of western Virginia in the summer and early fall of 1861, pro-Confederate unconventional combatants remained active in the region. Virginia Governor John Letcher issued a proclamation calling to "raise such a force as would enable General Floyd to recover Western Virginia from the invaders." On March 27, 1862, Virginia Legislature passed an Act to Authorize the Organization of ten or more Companies of Rangers, known as the Virginia Ranger Act.

On April 8, 1862, a bill was introduced to the 1st Confederate States Congress by a member of the Confederate Congress from Virginia to allow raising a force of partisan Rangers with a five dollar bounty for every dead federal. The Confederate Senate Congressional Military Committee removed the bounty provision, and proposed permitting future partisan Rangers to receive the same pay as regular Confederate soldiers on conditions they were subject to Confederate States Army regulations. In one exception, partisan Rangers were authorised to sell captured arms and munitions to Confederate Quartermaster-General's Department.

The Confederate Congress passed the Partisan Ranger Act on April 21, 1862.^{[citation needed]}

There were two purposes of the Partisan Ranger Act. One was control of unconventional warfare forces and employ them for the Confederate States advantage. The other purpose was to promote the use of unconventional warfare in areas outside the reach for the Confederate Army.^{[citation needed]}

According to Document 94 of the Congress of the Confederate States, the Partisan Ranger Act reads as follows:

Section 1. The congress of the Confederate States of America do enact, the president be, and he is hereby authorized to commission such officers as he may deem proper with authority to form bands of Partisan rangers, in companies, battalions, or regiments, to be composed of such members as the President may approve for the purposes of unconventional warfare.