The Bolshoye Toko (Russian: Большое Токо) is a lake in Sakha, Russia. It has a surface of 82.6 square kilometres (31+7⁄8 square miles) and a catchment area of 919 square kilometres (355 square miles). Its outflow is the Mulam river, part the Uchur River basin. The lake is located in the Aldan Highlands, on the border of Sakha Republic and Khabarovsk Krai. River Utuk flows into the lake from the Toko-Stanovik subrange of the Stanovoy Highlands. It is the deepest lake in Yakutia.

• List of lakes of Russia

• Article in the Great Soviet Encyclopedia