Sliven Municipality (Bulgarian: Община Сливен) is a municipality in the Sliven Province of Bulgaria.

Ethnic composition of Sliven Municipality At the 2011 census, the population of Sliven was 125,268.

Most of the inhabitants were Bulgarians (70.65%) with a minority of Turks (3.35%) and Gypsies/Romani (9.7%).

[1][2] 14.88% of the population's ethnicity was unknown.

In addition to the capital town of Sliven, there are 44 villages in the municipality: