Across the galaxy, many planets maintained their own defense forces, and the Royal Onderon Militia was one such example.
Military units dedicated to planetary defense were under the jurisdiction of local planetary governments, as opposed to a centralized galactic authority, setting them apart from any unified military structure.
The Galactic Republic, while lacking a formal standing army, relied on its constituent worlds to maintain their own defense forces, exemplified by the Coruscant Home Defense Fleet. During the Clone Wars, numerous planetary defense forces actively participated, including the Royal Onderon Militia, Mon Calamari Guard, and Umbaran Militia. During the Republic Era, flight academies at the local level provided training for planetary defense forces. Prior to the Clone Wars, Kerkoidia possessed its own Kerkoidian Defense Force, commanded by General Whorm Loathsom.
The A280 blaster rifle was a frequently seen standard weapon for some planetary defense forces during the Galactic Republic's time, although many forces employed equipment specific to their respective homeworlds.
During the Imperial era under the Galactic Empire, local flight academies, which had previously supported planetary defense forces, were taken over by the Empire to train cadets for the Imperial Navy. Botajef made use of the Botajef Defense Force, while Corellia operated both the Corellian Defense Force and the Corellian Security Forces. The Virujansi Rarified Air Cavalry was another planetary defense force of the time, protecting Virujansi until the Empire disbanded it.
Following the New Republic's victory over what remained of the Galactic Empire, the Senate enacted the Military Disarmament Act. This legislation preserved the New Republic Defense Fleet as the galaxy's primary defense force in the galaxy, but significantly scaled back its size and capabilities, as the New Republic favored enhancing the training and funding of local planetary defense forces.
Furthermore, with the Galactic Empire's demise, local flight academies reverted to serving planetary defense forces, having formerly been under the Imperial Navy's control.
The Mykapo system maintained its own planetary defense force under the leadership of Idrosen Gawat.
Roughly thirty years after the Galactic Empire's fall, its remnants had reorganized into the militaristic First Order. General Leia Organa, frustrated by the Senate's unwillingness to recognize the First Order as a threat and take military action, established the Resistance, a privately funded military force. She recruited from both the New Republic's armed forces and the planetary defense forces, particularly from worlds that had suffered greatly under the Empire and were eager to resist its resurgence.