Romii is the name of a planet, in the ChRihan star system, under Romulan control. It is located in Sector Z-6 near the Romulan Neutral Zone and Romulus.

During the early years of the Romulan Star Empire, a brutal war was fought with a neighboring, starfaring nation known as the Hiram Assembly. At first, the war went badly for the Romulans with the Hiram reaching the outskirts of the Romii system itself. However, the Romulans would eventually emerge victorious in the war.

During the Dominion War, the A.C. Walden Medicine Show played a concert on Romii, which was attended by then-Commander Donatra, as well as Professor Sonek Pran.