Within the galactic landscape, the title of captain signified a leader. For example, a captain could be the person in command of a starship when not involved with any military. However, within military forces, such as the Imperial Navy or the Royal Naboo Security Forces, a captain represented a high-ranking officer entrusted with significant command duties, a considerable rank. Conversely, in the underworld, pirate captains, such as Hondo Ohnaka, Lassa Rhayme, Ought-Six, and Sidon Ithano, headed their individual pirate crews. It is worth noting that pirate captains could be ousted through mutiny, as demonstrated when Silvo was overthrown by his First Mate Brutus.
During the Republic Era, the Galactic Republic incorporated the role of captain within its Judicial Forces. Similarly, the Republic Defense Coalition during the High Republic Era also utilized captains, granting them command over their own RDC vessels. Later, in 22 BBY, the governing body established a formal army along with a navy. This newly formed Republic Military, primarily composed of clone troopers originating from the planet Kamino, employed the rank of captain across both its army and navy. These clone trooper officers holding this rank were known as Clone Captains, although officers who were not clone could also hold the rank of captain.
Many clone navigation officers, some of whom were captains, sported a rank plaque featuring a single row of two red and one blue square (from left to right). Within the army structure, Clone Captains commanded companies consisting of 144 troopers, reporting directly to a Clone Commander. However, given the flexible command structures often adopted by Jedi Generals, some captains collaborated directly with their Jedi superiors. A prime example is Clone Captain Rex, a distinguished Clone Officer. Rex led the 501st Legion's Torrent Company and worked directly with Jedi General Anakin Skywalker, acting as the Jedi's second in command.
Initially, Clone Captains wearing standard Phase I armor were identified by maroon markings on their white armor. Many captains began personalizing their armor to express their individuality, represent their company's identity, and to avoid easy targeting by snipers.
The Confederacy of Independent Systems also utilized the rank of captain. Both organic officers and droids were eligible to hold this rank within the Separatist Droid Army. Rackham Sear, a male Kage Warrior, held the rank of captain in the Confederacy military. Furthermore, the Separatists deployed commando droid captains; one such captain was stationed at the Citadel.
The Confederacy navy also recognized the rank. Captain Mar Tuuk served in the Confederacy navy, commanding the Ryloth blockade from his Lucrehulk-class Battleship.
During the era of the First Galactic Empire, the ranks of captain existed within both the Imperial Navy and the Imperial Army. A stormtrooper captain from the army acted as a military advisor to Queen Trios of Shu-Torun.
The Imperial insignia plaque denoting the rank for navy officers consisted of three red squares above three blue. Security officers, on the other hand, wore a single row of six yellow squares. Army officers wore three red squares followed by one blue square.
The term "captain" could also be applied to anyone commanding a vessel, irrespective of their official military rank. Thrawn captained the Chimaera while holding the rank of commodore. His career advanced, ultimately leading to his promotion to Grand Admiral.
Within the Alliance to Restore the Republic, the rank of captain was present in both the army and the navy.
The insignia distinguishing a Rebel captain featured two pips stacked vertically. The color of these pips (red, blue, or green) indicated the specific branch of service.
This was also in effect during the early stages of the rebellion.
The First Order had captains in both its navy and Army. Notable captains within the army's Stormtrooper Corps included Cardinal and Phasma.
The First Order's rank structure was indicated by a combination of uniform color and arm insignia, displayed on the left sleeve. First Order captains wore a gray uniform with a black armband trimmed in silver, inscribed with the name of Dillon, a revered Imperial hero from the Galactic Civil War, rendered in silver Aurebesh characters.
Within the Resistance, captains served in both the army and the navy.
The rank badge for Resistance captains displayed a colored vertical line, with red signifying army personnel and blue representing the navy.
Within the Resistance Army, the rank of Captain was below that of Commander.
The rank of lieutenant was part of the E'ronoh's military. Jerrod Segaru held the rank of lieutenant and served as an advisor to the E'ronoh royal family.