The Shelon is a river in the northwest part of European Russia, in Dedovichsky, Porkhovsky, and Dnovsky Districts of Pskov Oblast and Soletsky and Shimsky Districts of Novgorod Oblast. The Shelon is one of the principal tributaries of Lake Ilmen. It has a length of and drains a basin of . The towns of Porkhov and Soltsy, as well as urban-type settlements of Dedovichi and Shimsk, are located on the banks of the Shelon River. The principal tributaries of the Shelon are the Sudoma (left), the Belka (right), the Polonka (right), the Uza (left), the Udokha (left), the Sitnya (left), and the Mshaga (left).