Ulan-Ude is the capital city of Buryatia, Russia, located about 100 kilometers southeast of Lake Baikal on the Uda River at its confluence with the Selenga. According to the 2021 Census, 437,565 people lived in Ulan-Ude; up from 404,426 recorded in the 2010 Census, making the city the third-largest in the Russian Far East by population.