| Official Name: | Zir Ahak |
| Native Name: | زيراهك |
| Settlement Type: | village |
| Pushpin Map: | Iran |
| Mapsize: | 150px |
| Subdivision Type: | Country |
| Subdivision Type1: | Province |
| Subdivision Name1: | Bushehr |
| Subdivision Type2: | County |
| Subdivision Name2: | Tangestan |
| Subdivision Type3: | Bakhsh |
| Subdivision Name3: | Delvar |
| Subdivision Type4: | Rural District |
| Subdivision Name4: | Bu ol Kheyr |
| Population As Of: | 2006 |
| Population Total: | 138 |
| Population Density Km2: | auto |
| Timezone: | IRST |
| Utc Offset: | +3:30 |
| Timezone Dst: | IRDT |
| Utc Offset Dst: | +4:30 |
| Coordinates: | 28.2928°N 51.2286°W |
Zir Ahak (fa|زيراهك, also Romanized as Zīr Āhak; also known as Zāyer, Zīrak, Zīrehak, Zīrehat, Zīreh Hak, Zirhak, and Zīr Rāh) is a village in Bu ol Kheyr Rural District, Delvar District, Tangestan County, Bushehr Province, Iran. At the 2006 census, its population was 138, in 34 families.