- See Masada for other articles with titles that contain, either by relationship or by coincidence, this character's surname.
Guillermo Masada was a male human in Starfleet in the 23rd century.
As of 2266, Masada held the rank of lieutenant, and served as science officer and second officer of the USS Constellation under Commodore Matthew Decker. (TOS - The Brave and the Bold, Book One novella: The First Artifact)
Masada perished, along with the rest of the Constellation crew, during that ship's encounter with an alien "planet killer" in 2267. (TOS episode: "The Doomsday Machine")
In an alternate timeline, Masada was assigned to the UESS Enterprise as science officer in 2264. (Star Trek: Myriad Universes novel: A Less Perfect Union)