| Official Name: | Ust-Syamzhenets |
| Native Name: | Усть-Сямженец |
| Settlement Type: | Village |
| Pushpin Map: | Russia Vologda Oblast#Russia |
| Subdivision Type: | Country |
| Subdivision Name: | Russia |
| Subdivision Name1: | Vologda Oblast |
| Subdivision Name3: | Kichmengsko-Gorodetsky District |
| Subdivision Type4: | Municipality |
| Utc Offset1: | +3:00 |
| Coordinates: | 59.8167°N 72°W[1] |
Ust-Syamzhenets (Russian: Усть-Сямженец) is a rural locality (a village) in Kichmegnskoye Rural Settlement, Kichmengsko-Gorodetsky District, Vologda Oblast, Russia. The population was 38 as of 2002.[2]
Ust-Syamzhenets is located 108 km southwest of Kichmengsky Gorodok (the district's administrative centre) by road. Vysokaya is the nearest rural locality.[3]