Sesimbra is a municipality of Portugal, in the Setúbal District, lying at the foothills of the Serra da Arrábida, a mountain range between Setúbal and Sesimbra. Due to its particular position at the Setúbal Bay, near the mouth of the Sado River and its natural harbour, it is an important fishing town. The population in 2011 was 49,500, in an area of 195.47 km². The present Mayor is Francisco Jesus.