The Battle of the Vikhra River (Russian: Битва на реке Вихре, Belarusian: Мсціслаўская бітва) took place on 29 April 1386 on the Vikhra River, tributary of the Sozh River, near Mstislavl between the Grand Duchy of Lithuania and the Principality of Smolensk. Lithuanians achieved a decisive victory and Smolensk was forced to accept being a vassal of Lithuania.