The Chikoy (; , Tsökh gol; , Sükhe gol) is a river in Zabaykalsky Krai and the Buryat Republic in Russia, which partially flows along the Russia-Mongolia border. It is a right tributary of the Selenga. The length of the Chikoy is . The area of its basin is .
The Chikoy has its source in the Chikokon Range, in the northern slopes of the Bystrinsky Golets peak. Its valley forms the northwestern limit of the Khentei-Daur Highlands. The river usually freezes over in late October or early November and stays icebound until April or early May. Its largest tributary is the Menza.