J-1 proton cannons were a form of droid artillery used by the Confederacy of Independent Systems during the Clone Wars against the Galactic Republic. They were deployed by the Separatists on the planets Ryloth, Geonosis, and Anaxes
During the Confederacy of Independent Systems's occupation of Ryloth, the tactical droid, TX-20 and his battle droids set up a battery of five of these proton cannons in the city Nabat. When the Republic Grand Army attempted to land there, the cannons were able to destroy one of the three assault ships. The cannons were then destroyed when Jedi General Obi-Wan Kenobi commandeered one.
- Star Wars: The Clone Wars – "Innocents of Ryloth" (First appearance)
- Star Wars: The Clone Wars – "Landing at Point Rain"
- Star Wars: The Clone Wars – "Unfinished Business"
- Star Wars: Absolutely Everything You Need to Know (First identified as J-1 proton cannon)