| Back River (Boothbay, Maine) | |
| Subdivision Type1: | Country |
| Subdivision Name1: | United States |
| Subdivision Type2: | State |
| Subdivision Name2: | Maine |
| Subdivision Type5: | Municipality |
| Subdivision Name5: | Boothbay |
| Length: | 4.8miles |
| Source1: | Cross River |
| Source1 Coordinates: | 43.9275°N -69.662°W |
| Mouth: | Sheepscot River |
| Mouth Location: | Sawyer Island |
| Mouth Coordinates: | 43.8755°N -69.6825°W |
The Back River is a 4.8adj=midNaNadj=mid[1] tidal channel in the town of Boothbay, Maine, in the United States. It defines the east and south sides of Barters Island and connects with the Sheepscot River, which forms the west side of the island. The Cross River joins the north end of the Back River with the Sheepscot River to the west.
Approximately north of where the river joins the Sheepscot River, another waterway of the same name connects with the Sheepscot River.