Caldas da Rainha () is a medium-sized city in the district of Leiria of Portugal. The city serves as the seat of the larger municipality of the same name and of the Comunidade Intermunicipal do Oeste (OesteCIM, Intermunicipal Community of the West). At the 2011 census, the municipality had a population of 51,729 in an area of , with 30,343 residing in the city. Although the city itself lies about inland, three of the municipality's civil parishes lie on the Atlantic Ocean. Caldas da Rainha is best known for its sulphurous hot springs and ceramic pottery.