| Tvarditsa Municipality | |
| Settlement Type: | Municipality |
| Pushpin Map: | Bulgaria |
| Pushpin Map Caption: | Location of Tvarditsa Municipality in Bulgaria |
| Coordinates: | 42.7°N 79°W |
| Subdivision Type: | Country |
| Subdivision Type1: | Province |
| Subdivision Name1: | Sliven Province |
| Seat Type: | Capital |
| Seat: | Tvarditsa |
| Unit Pref: | Metric |
| Area Total Km2: | 442.5 |
| Population Total: | 13,804 |
| Population As Of: | 2011 |
| Population Density Km2: | auto |
| Postal Code Type: | Postal code |
| Postal Code: | 8890 |
| Area Code Type: | Area code |
| Area Code: | 0454 |
Tvarditsa Municipality (Bulgarian: Община Твърдица) is a municipality in the Sliven Province of Bulgaria.
At the 2011 census, the population of Tvarditsa was 13,804. Most of the inhabitants were Bulgarians (67.79%) with a minority of Turks (9.32%) and Gypsies/Romani (15.21%).[1] [2] 7.07% of the population's ethnicity was unknown.
In addition to the capital town of Tvarditsa, there are 9 villages in the municipality: