| Official Name: | Muscle Ridge Islands, Maine |
| Settlement Type: | Unorganized territory |
| Pushpin Label Position: | left |
| Pushpin Map Caption: | Location within the state of Maine |
| Mapsize: | 260px |
| Subdivision Type: | Country |
| Subdivision Name: | United States |
| Subdivision Type1: | State |
| Subdivision Name1: | Maine |
| Subdivision Type2: | County |
| Subdivision Name2: | Knox |
| Unit Pref: | Imperial |
| Area Total Km2: | 128.6 |
| Area Land Km2: | 2.45 |
| Area Water Km2: | 126.2 |
| Area Total Sq Mi: | 49.7 |
| Area Land Sq Mi: | 0.95 |
| Area Water Sq Mi: | 48.7 |
| Population As Of: | 2020 |
| Population Total: | 9 |
| Timezone: | Eastern (EST) |
| Utc Offset: | -5 |
| Timezone Dst: | EDT |
| Utc Offset Dst: | -4 |
| Coordinates: | 44.0419°N -69.0386°W |
| Postal Code Type: | ZIP code |
| Area Code: | 207 |
| Blank Name: | FIPS code |
| Blank Info: | 23-47962 |
| Blank1 Name: | GNIS feature ID |
| Blank1 Info: | 1934678 |
Muscle Ridge Islands is an archipelago and unorganized territory off the coast of South Thomaston in Knox County, Maine, United States. The population was 9 at the 2020 census.[1]
According to the United States Census Bureau, the unorganized territory has a total area of 49.7 square miles (128.6 km2), of which 0.95 square miles (2.45 km2) is land and 48.7 square miles (126.2 km2) is water (98%).[2] The archipelago includes over a dozen islands, including Andrews, Dix, Fisherman, Pleasant, Graffam, and Two Bush Island, which is home to the Two Bush Island Light.[3]