| Serga | |
| Subdivision Type1: | Country |
| Subdivision Name1: | Russia |
| Subdivision Type3: | Region |
| Subdivision Name3: | Murmansk Oblast |
| Length: | 38km (24miles) |
| Source1: | Lake Sergozero |
| Mouth: | Varzuga |
| Mouth Coordinates: | 66.4505°N 36.4362°W |
| Progression: | Varzuga→ White Sea |
The Serga (Russian: Серга) is a river in the south of the Kola Peninsula in Murmansk Oblast, Russia. It is long, and has a drainage basin of . The Serga originates from the Lake Sergozero and flows into the Varzuga.