| Official Name: | Kohneh Deh Dum |
| Native Name: | كهنه ده دوم |
| Settlement Type: | village |
| Pushpin Map: | Iran |
| Mapsize: | 150px |
| Subdivision Type: | Country |
| Subdivision Type1: | Province |
| Subdivision Name1: | West Azerbaijan |
| Subdivision Type2: | County |
| Subdivision Name2: | Mahabad |
| Subdivision Type3: | Bakhsh |
| Subdivision Name3: | Central |
| Subdivision Type4: | Rural District |
| Subdivision Name4: | Akhtachi-ye Gharbi |
| Population As Of: | 2006 |
| Population Total: | 32 |
| Population Density Km2: | auto |
| Timezone: | IRST |
| Utc Offset: | +3:30 |
| Timezone Dst: | IRDT |
| Utc Offset Dst: | +4:30 |
| Coordinates: | 36.7067°N 45.7794°W |
Kohneh Deh Dum (Persian: كهنه ده دوم, also Romanized as Kohneh Deh Dūm; also known as Kohneh Deh) is a village in Akhtachi-ye Gharbi Rural District, in the Central District of Mahabad County, West Azerbaijan Province, Iran. At the 2006 census, its population was 32, in 9 families.