| South Branch Birch River | |
| Mouth Location: | Birch River |
| Subdivision Type1: | Country |
| Subdivision Name1: | United States |
| Length: | about 9miles |
The South Branch Birch River is a 9.4adj=midNaNadj=mid[1] river in Aroostook County, Maine, in the United States. From the outlet of a small pond (47.0591°N -68.8361°W) in Maine Township 16, Range 9, WELS, it runs southeast and east to its confluence with the North Branch in the town of Eagle Lake to form the Birch River. It is part of the Fish River watershed, draining north to the Saint John River, which flows southeast to the Bay of Fundy in New Brunswick, Canada.