| Official Name: | Millbrook Colony, South Dakota |
| Settlement Type: | Census-designated place |
| Pushpin Map: | South Dakota#USA |
| Pushpin Label: | Millbrook Colony |
| Coordinates: | 43.67°N -97.8717°W |
| Subdivision Type: | Country |
| Subdivision Name: | United States |
| Subdivision Type1: | State |
| Subdivision Name1: | South Dakota |
| Subdivision Type2: | County |
| Subdivision Name2: | Hanson |
| Area Footnotes: | [1] |
| Area Total Sq Mi: | 0.24 |
| Area Land Sq Mi: | 0.23 |
| Area Water Sq Mi: | 0.00 |
| Area Total Km2: | 0.62 |
| Area Land Km2: | 0.61 |
| Area Water Km2: | 0.01 |
| Population As Of: | 2020 |
| Population Footnotes: | [2] |
| Population Density Km2: | 161.55 |
| Timezone: | Central (CST) |
| Utc Offset: | -6 |
| Timezone Dst: | CDT |
| Utc Offset Dst: | -5 |
| Elevation Ft: | 1319 |
| Postal Code Type: | ZIP Code |
| Postal Code: | 57301 (Mitchell) |
| Area Code: | 605 |
| Blank Name: | FIPS code |
| Blank Info: | 46-42440 |
| Blank1 Name: | GNIS feature ID |
| Blank1 Info: | 2813031 |
| Population Total: | 98 |
| Unit Pref: | Imperial |
| Population Density Sq Mi: | 418.80 |
Millbrook Colony is a Hutterite colony[3] and census-designated place (CDP) in Hanson County, South Dakota, United States. The population was 98 at the 2020 census.[4] It was first listed as a CDP prior to the 2020 census.
It is in the western part of the county, 7miles by road west-northwest of Alexandria, the county seat, and 10miles east-southeast of Mitchell.