The Dopa system was an inhabited star system in Cardassian space.

Following the discovery of the attack on Korma by a Klingon Bird-of-Prey commanded by K'Temang in 2372, Kira Nerys inquired as to the distance of the nearest Cardassian warship; Gul Dukat guessed that the closest warship was probably somewhere in the Dopa system, a three day journey from Korma.

Later, when Dukat laid a trap for the same Bird-of-Prey, he claimed that his freighter, the Groumall, was carrying replicator and transporter components to the Dopa system. (DS9: "Return to Grace")

According to Star Trek: Star Charts (p. 46) and Stellar Cartography: The Starfleet Reference Library ("Federation Historical Highlights, 2161-2385"), the Dopa system was located in the Alpha Quadrant. This was a binary system with a G-class star and a F-class star.