Lya III was the third planet in the Lya planetary system. This system was located in Sector 30. Lya III was the location of a Federation starbase. Vice Admiral Haden was based at the starbase on Lya III. (TNG: "The Defector")

After completing its mission at Angosia III, Lya III was the destination of the USS Enterprise. (TNG: "The Hunted")