The Coridan system was an inhabited star system. A planet in this system, Coridan, was the homeworld for the Coridans, a warp-capable humanoid species. Other planets in this system were colonized by this species prior to 2151.
Prior to the Babel Conference of 2268, the Coridan system was claimed by some Federation races, and there were reports by Starfleet Intelligence that Orion smugglers had been raiding the system. After the conference, the Coridan planets were admitted to the United Federation of Planets. The system was located near to the planets Orion and Vulcan, and several unidentified neutral worlds. (TOS: "Journey to Babel"; DS9: "In the Cards"; ENT: "Demons")