Caldas da Rainha is a medium-sized city located in the Oeste region of Portugal, within the district of Leiria and the historical province of Estremadura. It serves as the seat of both the municipality of Caldas da Rainha and the Comunidade Intermunicipal do Oeste.
The city is situated approximately 10.5 kilometres inland, though three civil parishes within its municipality border the Atlantic Ocean. According to the 2011 census, the municipality covered an area of 255.69 square kilometres with a total population of 51,729, of which 30,343 resided specifically in the city.
Caldas da Rainha is primarily recognized for its sulphurous hot springs and its traditional ceramic pottery.