Ion cannons were a form of armament that fired ionized particles capable of disrupting electronic systems. Larger types could even disable a large capital ship, such as the Mega-ion cannons that were mounted on the side of the Subjugator-class heavy cruiser Malevolence, the v-150 planetary ion cannon used by the Alliance to Restore the Republic, or the broadside ion cannons equipped on the MC80 Liberty Type Heavy Star Cruiser. During the Battle of Scrim Island, continued fire from several planetary ion cannons dealt a considerable amount of damage to the hull of at least one Arquitens-class light cruiser.
The Eta-2 Actis-class light interceptor featured ion cannons that shot bursts of plasma that would cause temporary electrical disruptions to a target upon impact.
Y-wing starfighters were also equipped with ion cannons, most notably those used by the Alliance's Gold Squadron. Though their field of fire was somewhat limited, the ion cannons were quite powerful, with three blasts being sufficient to disable an Arquitens-class command cruiser and only one to completely disable a TIE/d "Defender" Multi-Role Starfighter starfighter. This was demonstrated during a skirmish in the Archeon Nebula.
A capital ship ion cannon battery firing
Early in the Clone Wars, the Confederacy of Independent Systems equipped the massive Subjugator-class heavy cruiser, the Malevolence, with immense ion cannons. With General Grievous in command, the Malevolence attacked dozens of Republic warships and ensured the ion cannons' secrecy from the Republic. Following the Battle of Abregado, the Republic learned of the ion cannons.
The Malevolences ion cannons were then disabled by the Republic's Shadow Squadron during the battle near the Kaliida Nebula. The Malevolence was later destroyed when Jedi General Anakin Skywalker sabotaged the ship and caused it to crash into the Dead Moon of Antar.
An MC75 cruiser disables a TIE fighter with an ion blast.
During the Galactic Civil War against the Galactic Empire, the Y-wing bombers of the Rebellion's Gold Squadron were equipped with ion cannons. MC75 Star Cruisers used by the Rebel Alliance were armed with heavy ion emplacements.
In 3 ABY, during the evacuation of their Echo Base on Hoth, the Rebel Alliance used a stationary ion cannon to disable Star Destroyers of the blockading Death Squadron, thereby allowing rebel vessels to escape from the star system. By the later stages of the Galactic Civil War, a number of MC80 Liberty Type Heavy Star Cruisers were outfitted with three portside ion cannons.
When the Resistance launched an attack on the Sith Eternal stronghold Exegol to prevent the launch of the Final Order fleet, Allegiant General Enric Pryde ordered the fleet's densly-packed Xyston-class Star Destroyers to open fire using only their ion cannons, to minimize damage from potential friendly fire.
- LEGO Star Wars: The Freemaker Adventures — "Escape from Coruscant"