Irkut (Russian: Ирку́т, Mongolian: Эрхүү гол Buryat: Эрхүү гол) is a river in the Buryat Republic and Irkutsk Oblast of Russia. It is the Angara River's left tributary. The length of the river is 488 kilometers (303 mi). The area of its basin is 15,000 square kilometers (5,800 sq mi). The Irkut River freezes up in late October or mid-November and stays icebound until late April or early May.