Bounding communes are: Carini, Cinisi, San Vito Lo Capo, Balestrate, Partinico and Trappeto.

The name Terrasini probably derives from Latin "terra sinus" = "land at the gulf" (the Gulf of Castellamare) or from "terra sinorum" = "land of the bays" due to the strongly curved coastline with a large number of larger and smaller bays.

The name was first cited for the region in a letter from the archive of the abbey San Martino delle Scale near Monreale of 24 November 1350 as "terras vocatas li Terrasini".

The origin of the town goes back to the late medieval times to a small settlement (called Favarotta) of agricultural workers on the large-scale landed property of the family "La Grua Talamanca" from Carini.

Modern Terrasini was founded 24 October 1836, when King Ferdinand II issued a decree that the village Favarotta, then considered part of neighboring Cinisi, should be merged with adjoining Terrasini as a single community.