Santiago do Cacém, officially the City of Santiago do Cacém, is a town and a municipality in Setúbal District in Portugal. The population in 2011 was 29,749, in an area of 1059.69 km<sup>2</sup>.
The present mayor is ÃÂlvaro Beijinha, elected by the Unitary Democratic Coalition. The municipal holiday is July 25.
Administratively, the municipality is divided into eight civil parishes (freguesias):
Santiago do Cacém is twinned with: