According to the opinion of historians and geographers such as Ptolemy, Diodorus Siculus and Strabo, Castellammare del Golfo was born as Emporium Segestanorum, port of Segesta, a nearby city which shared the same ordeals until its fall.

The Arabs Invaded Castellammare del Golfo from 827 AD, and called it "Al Madarig", which means "The Steps", probably due to an uphill steep street leading from the harbour to the area of the fortified bastion.

The small town is also noted for having been the birthplace of many Sicilian-American Mafia figures, including Sebastiano DiGaetano, Salvatore Maranzano, Stefano Magaddino, Vito Bonventre, John Tartamella, and Joseph Bonanno.

As of today, New York City is home to the largest dispora of people that were either born in or who could trace their lineage back to Castellammare del Golfo.

From Castellammare del Golfo you can take a boat trip departing from Cala Marina to the Egadi Islands situated in front of Trapani.