Capoeta aydinensis sp. nov. is described from the Büyük Menderes River and the streams Tersakan, Dalaman, and Namnam in southwestern Turkey. It is distinguished from all other Anatolian Capoeta species by the following combination of characters: one pair of barbels; a plain brownish body coloration; a well-developed keel in front of the dorsal-fin origin; a slightly arched mouth; a slightly convex lower jaw with a well-developed keratinized edge; a weakly ossified last simple dorsal-fin ray, serrated along about 60%-70% of its length, with 14-20 serrae along its posterior edge; 58-71 total lateral line scales; 11-12 scale rows between lateral line and dorsal-fin origin; 7-9 scale rows between lateral line and anal-fin origin.