The Bytantay (Russian: Бытантай; Yakut: Бытантай, Bıtantay) is a river in the Republic of Sakha in Russia. It is a left hand tributary of the Yana, and is 620 kilometres long, with a drainage basin of 40,200 square kilometres.
The river begins in the eastern flank of the Verkhoyansk Range at an elevation of 1,280 metres. It heads roughly northeast with the Kular Range to the northwest and then joins river Yana from the left 532 kilometres from its mouth. There are more than two thousand lakes in the basin of the Bytantay.
