| Official Name: | Millboro, South Dakota |
| Pushpin Map: | South Dakota |
| Subdivision Type: | Country |
| Subdivision Name: | United States |
| Subdivision Type1: | State |
| Subdivision Name1: | South Dakota |
| Subdivision Type2: | County |
| Subdivision Name2: | Tripp |
| Timezone: | Central (CST) |
| Utc Offset: | -6 |
| Timezone Dst: | CDT |
| Utc Offset Dst: | -5 |
| Elevation Ft: | 2218 |
| Coordinates: | 43.0731°N -99.9689°W |
| Area Code: | 605 |
| Blank Name: | GNIS feature ID |
| Blank Info: | 1256469[1] |
Millboro is an unincorporated community in Tripp County, South Dakota, United States. Millboro is southwest of Colome.
Millboro was laid out in 1929, and named for a planned gristmill near the town site.[2]