| Official Name: | South Glastonbury, Montana |
| Settlement Type: | Census-designated place |
| Pushpin Map: | Montana |
| Subdivision Type: | Country |
| Subdivision Name: | United States |
| Subdivision Type1: | State |
| Subdivision Name1: | Montana |
| Subdivision Type2: | County |
| Subdivision Name2: | Park |
| Unit Pref: | Imperial |
| Area Footnotes: | [1] |
| Area Total Km2: | 46.17 |
| Area Land Km2: | 45.30 |
| Area Water Km2: | 0.87 |
| Area Total Sq Mi: | 17.83 |
| Area Land Sq Mi: | 17.49 |
| Area Water Sq Mi: | 0.34 |
| Population As Of: | 2020 |
| Population Total: | 277 |
| Population Density Km2: | 6.11 |
| Population Density Sq Mi: | 15.84 |
| Timezone: | Mountain (MST) |
| Utc Offset: | -7 |
| Timezone Dst: | MDT |
| Utc Offset Dst: | -6 |
| Elevation Ft: | 5151 |
| Coordinates: | 45.3258°N -110.8081°W |
| Area Code: | 406 |
| Blank Name: | GNIS feature ID |
| Blank Info: | 2652371 |
South Glastonbury is a census-designated place in Park County, Montana, United States. Its population was 284 as of the 2010 census.[2]