A capital ship was any armed military starship over one hundred meters long. Ships of this class ranged from small and nimble corvettes like the Corellian Engineering Corporation CR90 corvette to titanic Star Dreadnoughts, such as the Kuat Drive Yards Eclipse.

Ships of this class were typically designed for fleet warfare, often positioned in armadas stationed in high orbit around a strategic planet. They formed the primary attack groups in most fleets. There were, however, exceptions to the typical definition. For example, the Sienar Fleet Systems GAT-12 Skipray Blastboat was considered a capital ship because of its heavy armament, despite being a mere twenty-five meters in length and operating primarily in the role of a heavy assault starfighter.

These vessels were commonly fitted with ship-to-ship and anti-fighter defensive weaponry, ranging from heavy ion cannons to turbolaser turrets. Many capital-ship classes also served as carriers and were able to deploy starfighters, landing craft, and other resources as required.

Given their size, capital ships required relatively large crews, employing in some instances thousands of beings. An example was the Imperial-class Star Destroyer, which was 1,600 meters long and required a crew of 37,000 to operate at full efficiency. There were also examples that utilized substantially fewer active personnel, whether by means of advanced control systems or simple necessity, as in the cases of the Katana fleet and the Errant Venture, respectively.