Cartao was a terrestrial body located in the Expansion Region upon which an Imperial facility was built. When a group of dissidents stole the Imperial corvette Carrion Spike from Moff Wilhuff Tarkin and used it to attack Galidraan Station in 14 BBY, Cartao and its Imperial facility were considered as potential targets for the ship-jackers. They, along with Lantillies and Ice Station Beta on Anteevy, were listed as theorized targets by Vice Admiral Dodd Rancit of Naval Intelligence when he was questioned on the situation by Galactic Emperor Sheev Palpatine.
During the Galactic Civil War, the Rebel Alliance's 61st Mobile Infantry fought on Cartao. In 3 ABY, when the company was stranded on the manufacturing planet Sullust, the tentative Captain Hazram Namir asked Vifra, the head of engineering, whether she had been present for the fighting on Cartao. Vifra replied that she had only joined six months prior, and so Namir told her that he'd tell her about Cartao if she helped keep the Sixty-First alive.
Cartao was first mentioned in the 2014 canon novel Tarkin, written by James Luceno. In Star Wars Legends continuity, the planet Cartao first appeared in "Hero of Cartao" — Star Wars Insider 68–70, a serialized short story written by Timothy Zahn and released over issues 68, 69, and 70 of Star Wars Insider on June 3, July, and early September of 2003 respectively.