| Official Name: | Katnaghbyur |
| Native Name: | Կաթնաղբյուր |
| Pushpin Map: | Armenia |
| Mapsize: | 150px |
| Subdivision Type: | Country |
| Subdivision Name: | Armenia |
| Subdivision Type1: | Marz (Province) |
| Subdivision Name1: | Lori |
| Population As Of: | 2001 |
| Population Total: | 998 |
| Timezone: | |
| Utc Offset: | +4 |
| Coordinates: | 41.0375°N 44.2203°W |
| Elevation M: | 1650 |
Katnaghbyur (Armenian: Կաթնաղբյուր, also Romanized as Kat’naghbyur, Katnakhpyur, Katnagbyur, and Katnaghpyur; formerly, Koturbulag) is a hamlet in the Lori Province of Armenia.