Sigma Draconis IX was the ninth planet in the Sigma Draconis system. This planet, unlike the other planets in the system, had a highly inclined orbit that brought it close to the orbital path of Sigma Draconis VIII. This was one of six planets in this system that was not classified as M class.
The position and orbital path of Sigma Draconis IX was depicted on a system map that was displayed on the main viewscreen of the USS Enterprise bridge in 2268. (TOS: "Spock's Brain")
According to the Star Trek: Star Charts (pgs. 19, 44), Sigma Draconis IX was located in Sector 004 (Sigma Draconis sector).