| Official Name: | St. Pierre, Montana |
| Settlement Type: | Census-designated place |
| Mapsize: | 250px |
| Subdivision Type: | Country |
| Subdivision Name: | United States |
| Subdivision Type1: | State |
| Subdivision Name1: | Montana |
| Subdivision Type2: | County |
| Subdivision Name2: | Hill |
| Unit Pref: | Imperial |
| Area Footnotes: | [1] |
| Area Total Km2: | 20.92 |
| Area Land Km2: | 20.92 |
| Area Water Km2: | 0.00 |
| Area Total Sq Mi: | 8.08 |
| Area Land Sq Mi: | 8.08 |
| Area Water Sq Mi: | 0.00 |
| Population As Of: | 2020 |
| Population Total: | 364 |
| Population Density Km2: | 17.40 |
| Population Density Sq Mi: | 45.07 |
| Timezone: | Mountain (MST) |
| Utc Offset: | -7 |
| Timezone Dst: | MDT |
| Utc Offset Dst: | -6 |
| Coordinates: | 48.235°N -109.8233°W |
| Area Code: | 406 |
| Blank Name: | FIPS code |
| Blank Info: | 30-65537 |
St. Pierre is a census-designated place (CDP) in Hill County, Montana, United States, within the Rocky Boy Indian Reservation. The population of St. Pierre was 350 at the 2010 census,[2] up from 289 in 2000.
St. Pierre is located in southeastern Hill County at 48.235°N -109.8233°W (48.234885, -109.823352),[3] on the northwestern edge of the Bears Paw Mountains. It is bordered to the south and west by Chouteau County, to the north by Sangrey, and to the east by Rocky Boy's Agency. It is south of Havre, the Hill County seat, and southeast of Box Elder.
According to the United States Census Bureau, the St. Pierre CDP has a total area of 20.9km2, all land.[2]
As of the census[4] of 2000, there were 289 people, 76 households, and 69 families residing in the CDP. The population density was 35.8sp=usNaNsp=us. There were 80 housing units at an average density of 9.9/sq mi (3.8/km). The racial makeup of the CDP was 1.73% White, 0.35% African American, 97.58% Native American, and 0.35% from two or more races. Hispanic or Latino of any race were 0.35% of the population.
There were 76 households, out of which 52.6% had children under the age of 18 living with them, 50.0% were married couples living together, 25.0% had a female householder with no husband present, and 9.2% were non-families. 9.2% of all households were made up of individuals, and none had someone living alone who was 65 years of age or older. The average household size was 3.80 and the average family size was 3.91.
In the CDP, the population was spread out, with 38.8% under the age of 18, 10.0% from 18 to 24, 26.0% from 25 to 44, 19.0% from 45 to 64, and 6.2% who were 65 years of age or older. The median age was 26 years. For every 100 females, there were 107.9 males. For every 100 females age 18 and over, there were 103.4 males.
The median income for a household in the CDP was $40,750, and the median income for a family was $26,875. Males had a median income of $27,083 versus $26,917 for females. The per capita income for the CDP was $9,437. About 28.4% of families and 28.9% of the population were below the poverty line, including 36.8% of those under the age of eighteen and none of those 65 or over.