Sant Adrià de Besòs is a city and a municipality within the comarca of Barcelonès in Catalonia, north-eastern Spain. It is situated on the Mediterranean coast, at the mouth of river Besòs, extending to both sides of the estuary although the original settlement with the parish church lies on the left bank of the river, in the northern part of town. Sant Adrià is the smallest municipality of Barcelonès and has close ties with the neighbouring cities of Barcelona, Badalona and Santa Coloma de Gramenet, forming a uniform urban area within Barcelona metropolitan area.