Viana do Castelo is a municipality and seat of the district of Viana do Castelo in the Norte Region of Portugal. The population in 2021 was 85,778, in an area of 319.02 square kilometres. The urbanized area of the municipality, comprising the city, has a population of approximately 36,148 inhabitants, although the extended densely populated region reaches surrounding municipalities like Caminha and Ponte de Lima with a population above 150,000 inhabitants.