Algeria Shares the Longest Border with Mali (1,376 km)

Algeria has the longest border with Mali: 1,376 km (855 mi) across the Sahara/Sahel. Other Mali neighbors: Mauritania (2,237 km), Niger (821 km), Burkina Faso (1,000 km), Guinea (858 km), Senegal (419 km), Côte d'Ivoire (532 km). Wait—Mauritania's border is longer. Correction: Mauritania (2,237 km) > Algeria (1,376 km). The original answer was incorrect. Mauritania has the longest border with Mali.