Ukio, situated in the Abrion sector within the Outer Rim Territories of the galaxy, was a prosperous planet known for its agrarian abundance. It was linked via hyperlane to both Rishi and Molavar. The Ukians were the planet's indigenous people. In the final years of the Galactic Republic, Ukio served as a major source of food for the Core Worlds and the Republic as a whole. However, the Ukians grew dissatisfied with the Republic's perceived lack of support during the Secessionist Movement, which led to Ukio's eventual alignment with the Confederacy of Independent Systems.
The Clone Wars arose from the escalating tensions between the Republic and the Separatists. Planets of economic significance, such as Ukio, became key objectives in the war, which was primarily fought by clone troopers and battle droids. Despite its earlier affiliation with the CIS, Ukio once again became a vital supplier of grain for the Republic during the conflict. Following her escape from the Battle of Scarif in 1 BBY, Princess Leia Organa instructed Rebel Alliance Captain Raymus Antilles to pilot her CR90 corvette, the Tantive IV, to the planet Tatooine. To shake off any Imperial pursuit, Antilles did not take a direct route, instead making a detour from the Scarif system to Ukio, before continuing onward to Roon.