| Type: | town |
| Mandemar | |
| Region: | Southern Highlands |
| State: | nsw |
| Coordinates: | -34.4333°N 167°W |
| Pushpin Label Position: | left |
| Pushpin Map Caption: | Location in New South Wales |
| Lga: | Wingecarribee Shire |
| Postcode: | 2575 |
| Elevation: | 702 |
| Parish: | Berrima, Joadja |
| County: | Camden |
| Stategov: | Goulburn |
| Fedgov: | Hume |
| Dist1: | 133 |
| Dir1: | SW |
| Location1: | Sydney |
| Dist2: | 20 |
| Dir2: | W |
| Location2: | Mittagong |
| Dist3: | 86 |
| Dir3: | ENE |
| Location3: | Goulburn |
| Near-N: | High Range |
| Near-W: | Joadja |
| Near-E: | Berrima |
| Near-S: | Berrima |
Mandemar is a locality in the Southern Highlands of New South Wales, Australia, in Wingecarribee Shire. The village is situated east of the ghost town, Joadja and has its own NSW Rural Fire Service.
According to the, the population of Mandemar was 62. At the 2021 census, 64 residents were recorded.[1]