An ultraviolet satellite was an orbital device that can emit ultraviolet light.

A constellation of 210 ultraviolet satellites was placed in a permanent 72-mile altitude, in orbit around Deneva in 2267 at the order of James T. Kirk. The light they emitted by burning trimagnesite and trevium was powerful enough to reach through the planet's atmosphere to destroy an infestation of neural parasites. (TOS: "Operation -- Annihilate!")