| Derjon | |
| Subdivision Type1: | Country |
| Subdivision Name1: | Italy |
| Length Km: | 25.8 |
| Source1 Location: | Sellajoch, South Tyrol, Italy |
| Source1 Coordinates: | 46.5178°N 11.7556°W |
| Source1 Elevation: | 1470m (4,820feet) |
| Mouth: | Eisack |
| Mouth Location: | Waidbruck, South Tyrol, Italy |
| Mouth Coordinates: | 46.5994°N 11.5311°W |
| Basin Size Km2: | 199 |
The Derjon (lld|Derjon; it|Rio Gardena; de|Grödner Bach) is a stream in South Tyrol, Italy.