| Valle Fértil | |
| Native Name: | Departamento Pocito |
| Settlement Type: | Department |
| Coordinates: | -30.6667°N -93°W |
| Subdivision Type: | Country |
| Subdivision Name: | Argentina |
| Established Title: | Established |
| Seat Type: | Seat |
| Seat: | Villa San Agustín |
| Leader Title: | Mayor |
| Unit Pref: | Metric |
| Area Total Km2: | 6419 |
| Population Total: | 6864 |
| Population Density Km2: | auto |
| Population Demonym: | vallista |
| Postal Code Type: | Postal Code |
| Postal Code: | 5400 |
| Postal2 Code Type: | IFAM |
| Postal2 Code: | SJU017 |
| Area Code Type: | Area Code |
| Area Code: | 0264 |
| Blank Name Sec1: | Patron saint |
| Blank Info Sec1: | San Agustín |
Valle Fértil is a department of the province of San Juan (Argentina). Characterized by highly fertile landscapes and contains the Ischigualasto Provincial Park, also known as the Valley of the Moon, which is visited by tourists from around the world.
The Spaniards, upon their arrival, found the indigenous people referred to the area as "Chaj Nai--Paj", which means "green or fertile country of many rivers".
The main attraction is Ischigualasto, a strange landscape, in what may have been one of the most interesting stages of the earth's history, the Triassic period, the place known as the Valley of the Moon, for the apparent resemblance to a lunar landscape. It is a protected area for the preservation and study of strange geological formations, wildlife, flora and fossils.