| Official Name: | Qatar Aghaj |
| Native Name: | قطاراغاج |
| Settlement Type: | village |
| Pushpin Map: | Iran |
| Mapsize: | 150px |
| Subdivision Type: | Country |
| Subdivision Type1: | Province |
| Subdivision Name1: | Hamadan |
| Subdivision Type2: | County |
| Subdivision Name2: | Kabudarahang |
| Subdivision Type3: | Bakhsh |
| Subdivision Name3: | Shirin Su |
| Subdivision Type4: | Rural District |
| Subdivision Name4: | Shirin Su |
| Population As Of: | 2006 |
| Population Total: | 223 |
| Population Density Km2: | auto |
| Timezone: | IRST |
| Utc Offset: | +3:30 |
| Timezone Dst: | IRDT |
| Utc Offset Dst: | +4:30 |
| Coordinates: | 35.5692°N 48.4711°W |
Qatar Aghaj (Persian: قطاراغاج, also Romanized as Qaţār Āghāj; also known as Ghatar Aghaj, Qaţār Āqāj, and Qatrākhāj) is a village in Shirin Su Rural District, Shirin Su District, Kabudarahang County, Hamadan Province, Iran. At the 2006 census, its population was 223, in 48 families.