| Official Name: | Gaujiena |
| Settlement Type: | Village |
| Pushpin Map: | Latvia |
| Pushpin Map Caption: | Gaujiena's location in Latvia |
| Coordinates: | 57.5167°N 49°W |
| Subdivision Type: | Country |
| Subdivision Type1: | Municipality |
| Subdivision Name1: | Smiltene |
| Subdivision Type2: | Parish |
| Subdivision Name2: | Gaujiena |
| Unit Pref: | Imperial |
| Area Total Km2: | 1,43 |
| Area Total Sq Mi: | 1,43 |
| Population As Of: | 2021 |
| Population Total: | 501 |
| Postal Code: | LV-4339 |
Gaujiena (German: Adsel) is a village along the Gauja River in Gaujiena Parish, Smiltene Municipality, Latvia. It was the seat of a Komtur of the Teutonic Knights. The Gaujiena Castle was erected in the 13th century, but fell into disrepair in the 18th century.