| Zadrna | |
| Source1 Coordinates: | 50.6613°N 16.0289°W |
| Mouth Coordinates: | 50.7867°N 16.0392°W |
| Subdivision Type1: | Country |
| Length: | 16km (10miles) |
| Source1 Elevation: | 600m (2,000feet) |
| Mouth Elevation: | 440m (1,440feet) |
| Basin Size: | 112km2 |
Zadrna (de|Zieder) is a river in Lower Silesian Voivodeship in southwestern Poland, a right tributary of the Bóbr. It rises in the Góry Krucze range of the Central Sudetes near the village of Błażejów, close to the border with the Czech Republic.