| Official Name: | Gamnab |
| Native Name: | گمنآب |
| Settlement Type: | village |
| Subdivision Type: | Country |
| Subdivision Type1: | Province |
| Subdivision Name1: | Khuzestan |
| Subdivision Type2: | County |
| Subdivision Name2: | Andimeshk |
| Subdivision Type3: | Bakhsh |
| Subdivision Name3: | Alvar-e Garmsiri |
| Subdivision Type4: | Rural District |
| Subdivision Name4: | Mazu |
| Population As Of: | 2006 |
| Population Total: | 40 |
| Population Density Km2: | auto |
| Timezone: | IRST |
| Utc Offset: | +3:30 |
| Timezone Dst: | IRDT |
| Utc Offset Dst: | +4:30 |
Gamnab (Persian: گمنآب, also Romanized as Gamnāb) is a village in Mazu Rural District, Alvar-e Garmsiri District, Andimeshk County, Khuzestan Province, Iran. At the 2006 census, its population was 40, in 7 families.