Clone troopers are fictional characters from the Star Wars franchise created by George Lucas. First introduced in the live-action film Star Wars: Episode II – Attack of the Clones (2002), they have since appeared in various other Star Wars media, including Star Wars: Episode III – Revenge of the Sith (2005) and the animated series Star Wars: The Clone Wars (2008–2014; 2020), Star Wars Rebels (2014–2018), Star Wars: The Bad Batch (2021–2024), and Tales of the Jedi (2022–present) as well as comics, novels, and video games set in both the Star Wars Legends expanded universe and the current canon.

The clone troopers were soldiers who fought for the Galactic Republic during the Clone Wars and during the early rise of the Empire. All clone troopers are artificially produced soldiers, created at special cloning facilities on the planet Kamino from the DNA of bounty hunter Jango Fett to serve as the military of the Galactic Republic during the Clone Wars, which takes its name from the troopers. They are genetically engineered to age at twice the rate of a normal human in order to be ready for deployment much quicker, and be unquestionably loyal to the higher chain of command. During the Clone Wars, the clone troopers served under the command of the Jedi Order as they fought against the droid armies of the Confederacy of Independent Systems (CIS), a movement organized by numerous planets that sought to secede from the Republic. At the end of the war, Sheev Palpatine, the Republic's leader and secretly a Sith Lord who orchestrated the conflict to gain political power, issues Order 66, which brands the Jedi as traitors and forcibly compels the clone troopers, under the control of inhibitor chips implanted in their brains, to execute them. Following the formation of the Galactic Empire and the destruction of the cloning facilities on Kamino, clone troopers are slowly replaced by Imperial stormtroopers, non-clone human recruits.

During the development of The Empire Strikes Back, Lucas initially conceived a planet of clones, which is why the Clone Wars was mentioned for the first time in the original Star Wars (1977) film. The clone trooper armor was designed to suggest an evolution into the stormtroopers of the original trilogy, and it incorporated features from both the armor of stormtroopers and Boba Fett, revealed in Attack of the Clones to be an unaltered clone of Jango Fett. The armored troopers in Attack of the Clones and Revenge of the Sith are computer-generated images voiced by Temuera Morrison, who played Jango Fett. Younger clones were played by Bodie Taylor and Daniel Logan, who played the younger Boba. Clones not wearing helmets were played by both Morrison and Taylor, who wore chroma key body suits to isolate their heads, and some clone troopers featured a blend of the actors' features. Beginning with The Clone Wars film that launched the animated series of the same name, adult clone troopers are voiced by Dee Bradley Baker and young clone troopers are voiced by Logan. In Star Wars: Clone Wars (2003-2005), all clones were voiced by André Sogiluzzo.

Upon their debut in the Star Wars prequel trilogy, clone troopers received a mixed response from critics and audiences, due to their limited screen time and the films never explicitly stating that they were distinct from the original trilogy's stormtroopers; some felt that the implication of stormtroopers being soldiers created solely for war took away from the impact of the conflict. Reception of the clone troopers improved significantly with their portrayal in The Clone Wars, which introduced numerous clones with distinctive traits and personalities and made an effort to humanize them, exploring their relationships with the Jedi and fellow clones and their thoughts and feelings about the Clone Wars and their own existence. Since then, numerous Star Wars works set during the Clone Wars era have featured clone troopers as main characters, with many going on to become fan favorites. Clone troopers have become cultural icons, and a widely recognized element of the Star Wars franchise.

In writing The Empire Strikes Back, Leigh Brackett's first draft of the film initially developed Lando Calrissian as a clone from a planet of clones involved in the Clone Wars mentioned in A New Hope and were nearly made extinct by the war, but this concept was not featured in the final film. George Lucas later came up with the alternate concept of an army of clone shock troops from a remote planet used by the Republic in the war that followed. Lucas intended for the prequel trilogy to depict the evolution of the galaxy's fighting forces, and the clone troopers were the step after flawed battle droids.

Clone troopers were designed to strongly suggest the army's evolution into the Empire's stormtrooper army. Concept artist Jay Shuster said of the armor design, "It follows the formula for a lot of the prequel trilogy. Take something pre-conceived in the existing trilogy and de-generate it." Design Director Doug Chiang incorporated both features of the Boba Fett and stormtrooper armor into the design, acknowledging the "vague assertion in Star Wars lore" that Fett's armor was connected to those of the stormtroopers. Initial concept models implied that the first generation armor was thicker and bulkier than stormtrooper armor, and this characteristic was retained by the art department for Revenge of the Sith. Lucas expressed a desire for individualized trooper armor from the beginning of art development for Revenge of the Sith. Several variations were largely dictated by environmental needs, but others were influenced of the 2003 Clone Wars animated series and the desert stormtroopers of A New Hope. The clone trooper designs "progressed" closer toward the stormtrooper designs, and the film included variant designs similar to the sandtrooper, scout trooper, and snowtrooper armor of the original trilogy.

The designs of clone trooper in snow and cold weather gear, seen in season one of The Clone Wars, are heavily inspired by early concept and costume by Ralph McQuarrie, Joe Johnston, and John Mollo for The Empire Strikes Back.

In Attack of the Clones and Revenge of the Sith, all clone troopers are computer-generated images and are voiced by Temuera Morrison, who played the clone template Jango Fett. The child clone troopers were played by Daniel Logan, who also played Jango's clone son Boba Fett, and the clone troopers as young men were played by Bodie Taylor, who was cast for his resemblance to a younger Morrison. Taylor was filmed multiple times and composited to fill out crowded shots set in Tipoca City, and in some cases, such as for distant shots, he was entirely digital.