| Official Name: | Hajji Hasan |
| Native Name: | حاجي حسن |
| Settlement Type: | village |
| Pushpin Map: | Iran |
| Mapsize: | 150px |
| Subdivision Type: | Country |
| Subdivision Type1: | Province |
| Subdivision Name1: | Golestan |
| Subdivision Type2: | County |
| Subdivision Name2: | Kalaleh |
| Subdivision Type3: | Bakhsh |
| Subdivision Name3: | Central |
| Subdivision Type4: | Rural District |
| Subdivision Name4: | Aq Su |
| Population As Of: | 2006 |
| Population Total: | 314 |
| Population Density Km2: | auto |
| Timezone: | IRST |
| Utc Offset: | +3:30 |
| Timezone Dst: | IRDT |
| Utc Offset Dst: | +4:30 |
| Coordinates: | 37.4497°N 55.6128°W |
Hajji Hasan (Persian: حاجي حسن, also Romanized as Ḩājjī Ḩasan) is a village in Aq Su Rural District, in the Central District of Kalaleh County, Golestan Province, Iran. At the 2006 census, its population was 314, in 66 families.