下通古斯河（俄语：Нижняя Тунгуска）是一条位于西伯利亚的河流。流经俄罗斯伊尔库茨克州和克拉斯诺亚斯克边疆区，全长2,989公里，是叶尼塞河的右支。

Nizhnyaya Tunguska (Russian:Ни́жняя Тунгу́ска;IPA: [ˈnʲiʐnʲɪjə tʊnˈɡuskə], meaning Lower Tunguska) is a river in Siberia, Russia, that flows through the Irkutsk Oblast and the Krasnoyarsk Krai. The river is a right tributary of the Yenisei joining it at Turukhansk (see Siberian River Routes). Settlements on the river include Tura, Yukti and Simenga. The ice-free period on the Lower Tunguska starts in mid-June and ends in the first half of October.