The Plyussa is a river in Plyussky and Gdovsky Districts of Pskov Oblast and in Slantsevsky District of Leningrad Oblast in Russia. It is a right tributary of the Narva. It is 281 kilometres (175 mi) long, and the area of its basin 6,550 square kilometres (2,530 sq mi). The urban-type settlement of Plyussa and the town of Slantsy are located on the banks of the Plyussa.