| Official Name: | Kahnak |
| Native Name: | Persian: کهنک |
| Settlement Type: | village |
| Pushpin Map: | Iran |
| Mapsize: | 150px |
| Subdivision Type: | Country |
| Subdivision Type1: | Province |
| Subdivision Name1: | Tehran |
| Subdivision Type2: | County |
| Subdivision Name2: | Damavand |
| Subdivision Type3: | Bakhsh |
| Subdivision Name3: | Central |
| Subdivision Type4: | Rural District |
| Subdivision Name4: | Abarshiveh |
| Population As Of: | 2006 |
| Population Total: | 103 |
| Population Density Km2: | auto |
| Timezone: | IRST |
| Utc Offset: | +3:30 |
| Timezone Dst: | IRDT |
| Utc Offset Dst: | +4:30 |
| Coordinates: | 35.6903°N 52.4883°W |
Kahnak (Persian: کهنک, also Romanized as Kohnak; also known as Kahang) is a village in Abarshiveh Rural District, in the Central District of Damavand County, Tehran Province, Iran. At the 2006 census, its population was 103, in 37 families.