Kalyazin is a town located in the Tver Oblast of Russia. It serves as the administrative center of the Kalyazinsky District and is situated on the right bank of the Volga River.
The town is positioned approximately 175 kilometers (109 miles) northeast of Tver, which is the administrative center of the oblast. According to the 2010 census, the population of Kalyazin was 13,867, following a decline from 14,820 in 2002 and 15,544 in the 1989 Soviet census.