Dereağzı is a village in Bitlis District, in Bitlis Province, Türkiye. Dereağzı lies at 1,509 m above sea level, in the Southeastern Taurus mountains. It has 322 inhabitants. The nearest city is Bitlis, 17.6 km to the northwest. Among the landmarks around are Nemrut (37 km), Saint Anania monastery (16.8 km) and Amardolu Monastery (17.0 km).