Sofia is a region in northern Madagascar. It is named for the Sofia River. It is the second largest Malagasy region with an area of 50,100 km², an…Sofia is a region in northern Madagascar. It is named for the Sofia River. It is the second largest Malagasy region with an area of 50,100 km², and had a population of 1,500,227 in 2018. The administrative capital is Antsohihy.