The town of Cambrils can trace its origins back to prehistoric times, although it was not until the Roman period that the present town of Cambrils began to grow. This is evident from the archaeological sites found throughout the municipality, such as the Roman villa of La Llosa, strategically located alongside the Via Augusta and not far from the Roman capital of Tarraco.

By the mediaeval period there was already a permanent settlement on the right bank of the Alforja Torrent. From 1152 the kingdom of Aragon, having driven the Moors out of Catalonia, granted a series of privileges to encourage the repopulation of the place known as Cambrils. It was in the 12th century that the foundations were laid for the establishment of a stable population centre here at the southern gateway to the Camp de Tarragona, well connected to El Camino Real (the Royal Road) that linked Tortosa and Tarragona. The area also had good maritime connections; indeed, the troops of Jaume I sailed from these beaches in 1229 to re-conquer Majorca from the Moors.

Due to this strategic position, the Crown kept title over the town by establishing a feudal lord—vassal to the king-count—and a detachment of soldiers here. In addition, they built defensive walls and towers that also served to protect other nearby villages such as Els Tegells, Les Planes and Montbrió. This royal initiative lead to the development of the present-day Old Town, with a church, hostel, hermitage, hospital, convent, market, fair, artisans, and, above all, farmers who worked the rich lands surrounding Cambrils.