Ona Antilles was a Lieutenant in the Galactic Alliance Remnant, and was a Human female. Ona, belonging to the Antilles family, was the daughter of Bail Antilles, who previously served as a member of the Galactic Alliance Triumvirate.
When the Jedi delegation arrived and joined the fleet, Lieutenant Antilles was there. Following the attempted assassination of Admiral Gar Stazi, she briefly held the position of second-in-command of the fleet.
Antilles received a promotion to Admiral Stazi's personal aide when the Galactic Alliance Remnant established their headquarters in Pau City on Utapau. Jariah Syn and Deliah Blue were greeted by Antilles, who were looking to sell weapons to Stazi and requested a face-to-face meeting with him to negotiate. However, their real objective was to keep an eye out for any assassins dispatched by Vul Isen to target the Admiral. Syn identified the assassin and eliminated him before he could harm Stazi. Following this, Antilles suggested that the Admiral should immediately go back to his flagship, but he declined, citing the danger faced by their wounded.