| Official Name: | Flat Willow Colony, Montana |
| Settlement Type: | Census-designated place |
| Pushpin Map: | Montana#USA |
| Pushpin Label: | Flat Willow Colony |
| Coordinates: | 46.7242°N -108.4892°W |
| Subdivision Type: | Country |
| Subdivision Name: | United States |
| Subdivision Type1: | State |
| Subdivision Name1: | Montana |
| Subdivision Type2: | County |
| Subdivision Name2: | Musselshell |
| Unit Pref: | Imperial |
| Area Footnotes: | [1] |
| Area Total Sq Mi: | 0.13 |
| Area Land Sq Mi: | 0.13 |
| Area Water Sq Mi: | 0.00 |
| Area Total Km2: | 0.33 |
| Area Land Km2: | 0.33 |
| Area Water Km2: | 0.00 |
| Population As Of: | 2020 |
| Population Footnotes: | [2] |
| Population Total: | 15 |
| Population Density Sq Mi: | 117.19 |
| Population Density Km2: | 45.24 |
| Timezone: | Mountain (MST) |
| Utc Offset: | -7 |
| Timezone Dst: | MDT |
| Utc Offset Dst: | -6 |
| Elevation Ft: | 3507 |
| Postal Code Type: | ZIP Code |
| Postal Code: | 59072 (Roundup) |
| Area Code: | 406 |
| Blank Name: | FIPS code |
| Blank Info: | 30-26733 |
| Blank1 Name: | GNIS feature ID |
| Blank1 Info: | 2806653 |
Flat Willow Colony is a Hutterite community[3] and census-designated place (CDP) in Musselshell County, Montana, United States. It is in the northern part of the county, 5miles east of U.S. Route 87 and north-northeast of Roundup, the Musselshell county seat.
The community was first listed as a CDP prior to the 2020 census, at which time it had a population of 15.[2]
According to the U.S. Census Bureau, the colony has an area of 0.13sqmi, all land.[1]