Mempa IX was a planet, the ninth planet in the Mempa star system. Mempa IX was located in the Mempa sector of the Klingon Empire. During the Dominion War, Cardassian forces captured Mempa IX and established a base there. The planet was later recaptured by the Klingon Defense Force and the base destroyed, due to the actions of Bekk Wol, against the orders of her superior, Krantor. (GKN novel: A Good Day to Die)