| Aïn Defla | |
| Official Name: | Commune of Aïn Defla |
| Native Name: | عين الدفلى |
| Native Name Lang: | ⵉⵏ ⴷⴻⴼⵍⴰ |
| Type: | Municipality |
| Pushpin Map: | Algeria |
| Pushpin Map Caption: | Location of Aïn Defla within Algeria |
| Coordinates: | 36.2652°N 1.9703°W |
| Subdivision Type: | Country |
| Subdivision Name: |  Algeria |
| Subdivision Type1: | Province |
| Subdivision Name1: | Aïn Defla (seat) |
| Subdivision Type2: | District |
| Subdivision Name2: | Aïn Defla (coextensive) |
| Seat Type: | District seat |
| Leader Title: | PMA Seats |
| Leader Name: | 11 |
| Unit Pref: | Metric |
| Elevation M: | 980 |
| Population Total: | 65453 |
| Population As Of: | 2008 |
| Population Density Km2: | auto |
| Timezone1: | CET |
| Utc Offset1: | +01 |
| Postal Code Type: | Postal code |
| Postal Code: | 44000 |
| Blank Name: | ONS code |
| Blank Info: | 4401 |
| Blank1 Name: | Climate |
| Blank1 Info: | Csa |
Aïn Defla (Arabic: عين الدفلى, lit. oleander spring) is the capital city of Aïn Defla Province, Algeria. It is also a commune.[1]
In Roman times the city was called Oppidum Novum. The vestiges of the Oppidum Novum are still visible.
The current city was founded in the 20th century by a soldier named youcef afg of the rank of agha, with the idea of bringing together the indigenous populations from the villages of the region.
This region of uneven terrain, which was considered unstable and dangerous by the French during the Algerian War, had for this reason been declared a forbidden zone.
In the 1990s, the same region was a stronghold of the Armed Islamic Group (GIA).[2] There was fighting between militants and government troops in January 2021.[3]