Cloning was the process of growing a genetic duplicate from an original source. Thirty-two years before the Battle of Yavin, Jedi Master Sifo-Dyas commissioned the Kaminoan scientists to create an army of clone troopers for the Galactic Republic. Within a decade, the Republic mobilized the clone army in response to the secessionist movement of the Confederacy of Independent Systems, resulting in the outbreak of the Clone Wars.
The Kaminoan cloning production continued to engineer clones for the Republic throughout the conflict. With the end of the war, the clones initially served the Republic's successor government, the Galactic Empire, as stormtroopers. In time the Empire ceased its cloning production, decommissioned the clones, and turned to the recruitment of regular humans.
Cloning was the scientific procedure of growing a clone from the genetic template of a living organism. The original source's genetic code could be altered through modifications to the cloning process for various purposes, including growth acceleration and greater docility. Without alterations to the genome, a clone would be the exact duplicate of its template at the genetic level.
- "Two hundred thousand units are ready, with million more well on the way."
- ―Lama Su, to Obi-Wan Kenobi
The science of cloning was critical to the creation of the Kaminoan clone army in the waning years of the Galactic Republic. Prior to the rise of the Galactic Empire, the Kaminoan cloners were commissioned by Jedi Master Sifo-Dyas to engineer an army of clone soldiers for the Republic. However, Sifo-Dyas died shortly thereafter, allowing for the Sith to secretly take over the clone project. As the Kaminoans' new benefactors, the Sith provided them with the means to create and modify the clone army—specifically a template, the human bounty hunter Jango Fett whose genetic code served as the baseline for the clone troopers; and a control chip to ensure the clones' absolute obedience in the event of the activation of Clone Protocol 66. In addition to behavioral modification, the Kaminoans altered Fett's genotype to meet the deadline for the completion of the first generation of battle-ready units. As a result, the clones were designed to age at twice the rate of regular humans, and therefore grown to maturity in one decade.
Ten years after Sifo-Dyas' death, the Kaminoan cloning technology successfully produced 200,000 soldiers and an additional million units close to completion. By then the Jedi Order became aware of the army's existence, as well as Sifo-Dyas' role in its inception. With the galaxy on the verge of civil war as a result of the secessionist movement of the Confederacy of Independent Systems, the Republic mobilized the clone troopers against the newly-built Separatist Droid Army.
Throughout the Clone Wars, clone troopers were the backbone of the Grand Army of the Republic. However, the option of cloning supplementary units was a controversial politicial issue in the Galactic Senate of the Republic. While Senator Padmé Amidala and other like-minded politicians favored diplomacy as a means to end the conflict, others advocated for the escalation of war—including Halle Burtoni  whose homeworld, the extragalactic planet Kamino, gained representation in the Senate as a result of her people's role in the creation of the clone army. Seeking to promote the economic interests of Kamino, Burtoni successfully proposed an increase in the clone trooper production.
In the aftermath of the Clone Wars, the surviving clone troopers became the first stormtroopers of the Galactic Empire. In time the clones were decommissioned due to their accelerated aging process. Rather than continuing to rely on the Kaminoan cloning production, the stormtrooper ranks were opened to birth-born human recruits. By the time of the First Order–Resistance conflict, having grown disillusioned with the latest generation of stormtroopers, the Force warrior Kylo Ren contemplated the possibility of using the cloning process to create a more capable army for the First Order.
- Star Wars: Episode II Attack of the Clones
- Star Wars: The Clone Wars – "Clone Cadets"
- Star Wars: The Clone Wars – "Death Trap"
- Star Wars: The Clone Wars – "R2 Come Home"
- Star Wars: The Clone Wars – "Lethal Trackdown"
- Star Wars: The Clone Wars – "ARC Troopers"
- Star Wars: The Clone Wars – "Senate Murders" (Appears in flashback(s))
- Catalyst: A Rogue One Novel
- Star Wars: The Clone Wars – "Deception"
- Star Wars: The Clone Wars – "Bounty"
- Star Wars: The Clone Wars – "The Bad Batch"
- Star Wars: The Clone Wars – "A Distant Echo"
- Star Wars: Episode III Revenge of the Sith
- Ahsoka (Mentioned only)
- Star Wars: Episode IV A New Hope (Special Edition) (Mentioned only)
- Star Wars: Episode V The Empire Strikes Back (First appearance)
- Star Wars: Episode VI Return of the Jedi
- Bloodline (Mentioned only)
- "The Crimson Corsair and the Lost Treasure of Count Dooku"
- Star Wars: Episode VII The Force Awakens (Mentioned only)
- Star Wars: The Force Awakens novel (Mentioned only)
- Star Wars: The Force Awakens: A Junior Novel (Mentioned only)
- (First identified as Cloning)
- Star Wars: Absolutely Everything You Need to Know
- Star Wars: The Force Awakens: The Visual Dictionary
- Star Wars: Poe Dameron: Flight Log
- Star Wars: Galactic Atlas
- Star Wars: Rogue One: The Ultimate Visual Guide