Sigma Draconis III was the inhabited third planet in the Sigma Draconis system. Classified as M-class, this moonless world was the homeworld for the Sigma Draconis III natives.

The planet was larger and more heavily populated than Sigma Draconis IV. By 2268, the planet's inhabitants had a pre-spaceflight culture with an industrial scale rating of B, which was equivalent to Earth in 1485, and a technological rating of 3.

The position and orbital path of Sigma Draconis III was depicted on system maps that were displayed on the main viewscreen of the USS Enterprise bridge in 2268. (TOS: "Spock's Brain")

According to Star Trek: Star Charts (pp. 18, 19, 44) and Stellar Cartography: The Starfleet Reference Library ("Federation Historical Highlights, 2161-2385"), the Sigma Draconis system was located in Sector 004 (Sigma Draconis sector), in the Alpha Quadrant. This was a Federation system in the late 24th century.