The sea of Eastern Siberia Russian (: Восто́чно-Сиби́рскоемо́ре ) is a bordering Mer of the Arctic Ocean. It lies between the coast of Siberia in the south, the archipelago of the New Siberian Islandss in the west which separates it from the Mer of Laptev and the island of Wrangel in the east which separates it from the Mer of Tchouktches.

Its surface is of 913.000 km ². It is taken in the ices most of the year. Its depth is lower than 50 m on 70  % of its superficie  ; its more great depth is of 155 Mr. the coast which borders it is generally punt in the west to the mouth of Kolyma and mountainous in the east. The temperature of the air is of 0 with 2° C in summer (4°C in the south) and of -30° C in winter.

The sea was discovered at the 17th century by Russian navigators going from mouth in mouth. In 1648 Semyon Dezhnev and Fedot Alekseev discovered the coast of the mouth of Kolyma until that of Anadyr then until the Bering Strait. An exploration and a systematic cartography of the sea and its coasts were carried out within the framework of a series of forwardings in 1735 - 42, 1820 - 24, 1822, 1909 and 1911 - 14.

The principal port is Pevek.