| Ahvanu | |
| Native Name: | Persian: اهوانو |
| Native Name Lang: | fa |
| Settlement Type: | Village |
| Pushpin Map: | Iran |
| Coordinates Footnotes: | [1] |
| Subdivision Type: | Country |
| Subdivision Name: | Iran |
| Subdivision Type1: | Province |
| Subdivision Name1: | Semnan |
| Subdivision Type2: | County |
| Subdivision Name2: | Damghan |
| Subdivision Type3: | District |
| Subdivision Name3: | Central |
| Subdivision Type4: | Rural District |
| Subdivision Name4: | Rudbar |
| Unit Pref: | Metric |
| Population As Of: | 2016 |
| Population Total: | 776 |
| Population Density Km2: | auto |
| Timezone: | IRST |
| Utc Offset: | +3:30 |
Ahvanu (Persian: اهوانو) is a village in Rudbar Rural District of the Central District of Damghan County, Semnan province, Iran.
Nearby, Darius III was murdered by Bessus. The village was damaged in the 856 Damghan earthquake.
At the time of the 2006 National Census, the village's population was 606 in 172 households.[2] The following census in 2011 counted 650 people in 182 households.[3] The 2016 census measured the population of the village as 776 people in 270 households; it was the most populous village in its rural district.[4]