The Romans built the Pont Flavien in the 1st century BC, a triumphal bridge which crosses the River Touloubre.

[5] Saint-Chamas owes its name to Sanctus Amantius (Saint Amans, by tradition the first bishop of Rodez), in whose honour a chapel was built in the 7th century.

The settlement was initially constructed on the Baou, a chalk hill which overlooks the Étang de Berre, a site that was easy to defend and from which the surrounding region could be surveyed.

In 1690, construction was initiated by Louis XIV on the royal black powder mill, La Poudrerie; this remained for a long time the town's principal industry until it shut down in 1974.

The two main quarters, one of which developed around the town hall, the other in proximity to the port, were linked by a tunnel called la Goule which collapsed in 1863.