The Ilidarians are a technologically advanced species native to Ilidaria, in the Delta Quadrant. Neelix suggested that they might be able to assist when the USS Voyager attempted to rescue what appeared to be a vessel (actually a reflection of the Voyager herself) trapped in the event horizon of a quantum singularity in 2371, since he noted they were "quite friendly, most of time". (VOY: "Parallax")
Voyager crew members Lieutenant Commander Chakotay and Lieutenant Tuvok conducted a trade mission to the Ilidarians later that year. On the way back they were attacked by the Komar. (VOY: "Cathexis")