Elorrio is a town and a municipality located in the eastern part of the province of Biscay, in the Basque Country, in northern Spain. As of 2…Elorrio is a town and a municipality located in the eastern part of the province of Biscay, in the Basque Country, in northern Spain. As of 2017, it has a population of 7,307 inhabitants. It covers an area of 37.20 square kilometers and it has a population density of 193.58 people per square kilometer. It holds the medieval title of Most Loyal and Noble Villa.