| Ninthavur 21 | |
| Iso Code: | LK-5230105 |
| Coordinates: | 7.3422°N 81.8491°W |
| Subdivision Type: | Country |
| Subdivision Name: | Sri Lanka |
| Subdivision Type1: | Province |
| Subdivision Name1: | Eastern Province |
| Subdivision Type2: | District |
| Subdivision Name2: | Ampara District |
| Subdivision Type3: | Divisional Secretariat |
| Subdivision Name3: | Ninthavur Divisional Secretariat |
| Subdivision Type4: | Electoral District |
| Subdivision Name4: | Digamadulla Electoral District |
| Subdivision Type5: | Polling Division |
| Subdivision Name5: | Kalmunai Polling Division |
| Population Total: | 608 |
| Population As Of: | 2012[1] |
Ninthavur 21 Grama Niladhari Division is a Grama Niladhari Division of the Ninthavur Divisional Secretariat, of Ampara District, of Eastern Province, Sri Lanka.