Konstantinovsk is a town located in the Rostov Oblast of Russia. It serves as the administrative center of the Konstantinovsky District and is situated on the Don River near the Seversky Donets.
According to census data, the population of the town has remained relatively stable over recent decades. The 2010 census recorded a population of 17,926 residents, following figures of 18,801 in 2002 and 18,392 during the 1989 Soviet census.