In the Star Wars universe, battle droids are droids designed for combat, especially the ones used by the Trade Federation and Confederacy in the prequel trilogy.

Battle droids are designed to win through numbers, even though a swarm of battle droids can be cut down by only two Jedi knights. Battle droids are relatively mindless and, while apparently capable of some independent behaviour, are usually slaved to a central control mainframe, disallowing them to think on their own. This removes practically any ability to question orders or rise up against their masters, a very useful attribute for the monopolistic Trade Federation and other rich people whose motives for combat are not exactly pure.

Battle droids, as heretofore mentioned, are frequently controlled by outside devices, which can be located on starships or in other well-defended facilities. This means that if a control system is destroyed, the battle droids it controls become inactive. This occurred during the Battle of Naboo, in which Anakin Skywalker destroyed the droid control ship. The monumental defeat spurred interest in independent droids, and this technique gained ground following the battle.

Battle droid types are shown by color worn on the droid's head, shoulders and chest.

• None-standard infantry droid
• Blue-pilot droid
• Red-security droid
• Yellow-command droid

There are battle droid foundries on the planet Geonosis, which Anakin Skywalker and Padmé Amidala got caught in during Attack of the Clones. It is possible that the Battle Droids are modeled after the Geonosians, although other sources state they are based on Neimoidian skeletons.

Super battle droids were created for the Battle of Geonosis. Droidekas are another type of battle droid seen in the films.