The Messalo (Portuguese: Rio Messalo) is a major river of northeastern Mozambique. It flows through Niassa Province and Cabo Delgado Province, passes near Chai, and flows into the Mozambique Channel of the Indian Ocean at Quiterajo beach at (11°40′25″S40°26′25″E). The Messalo River is 530 km (330 mi) in length while the Messalo River Basin is 24,000 km² (9,300 sq mi) in size.