A prefect was a title that was given to an administrative official, who was often placed in a supervisory position over a district, planet, or sector. Amongst the civilizations to use the title were Argelians, Cardassians, Kelvans, and Troyians.
Prefect was the title used by the head of Vulcan's Offworld Service, first used by Savar, and later by T'Saaf. (TOS novel: Strangers from the Sky)
In 2267, Jaris held the position of prefect on Argelius II. (TOS episode: "Wolf in the Fold")
The ruler of Troyius was called Prefect-King. In 2268, this was Cosalthan II (FASA RPG module: The Orions: Book of Common Knowledge).
Between 2346 and 2369, Gul Skrain Dukat served as the Prefect of Bajor during the Cardassian Union's Occupation of Bajor. (DS9 episodes: "Emissary", "Wrongs Darker Than Death or Night")
In the late 26th century, Tamar held the position of prefect in the Kelvan Armada. (TOS - Strange New Worlds 9 short story: "Gone Native")