Gorno-Altaysk, city and administrative centre of Altay republic, southern Russia. It lies in the foothills of the Altai Mountains, along the Mayma River near its confluence with the Katun. Gorno-Altaysk is an agricultural centre and has a woodworking industry and cloth factories. Teacher-training and veterinary colleges and a historical institute are located there. It became a city in 1928. Pop. (2006 est.) 53,070.