| Saint Onge, South Dakota | |
| Settlement Type: | Census-designated place |
| Pushpin Map: | South Dakota#USA |
| Pushpin Label: | St. Onge |
| Pushpin Map Caption: | Location in South Dakota##Location in the United States |
| Subdivision Type: | Country |
| Subdivision Name: | United States |
| Subdivision Type1: | State |
| Subdivision Name1: | South Dakota |
| Subdivision Type2: | County |
| Subdivision Name2: | Lawrence |
| Unit Pref: | Imperial |
| Area Footnotes: | [1] |
| Area Total Km2: | 3.48 |
| Area Land Km2: | 3.48 |
| Area Water Km2: | 0.00 |
| Population As Of: | 2020 |
| Population Footnotes: | [2] |
| Population Total: | 170 |
| Population Density Km2: | 48.82 |
| Timezone: | Central (CST) |
| Utc Offset: | -6 |
| Timezone Dst: | CDT |
| Utc Offset Dst: | -5 |
| Elevation Ft: | 3432 |
| Coordinates: | 44.5458°N -103.7197°W |
| Postal Code Type: | ZIP code |
| Postal Code: | 57779 |
| Blank Name: | FIPS code |
| Blank Info: | 46-57260 |
| Blank1 Name: | GNIS feature ID |
| Blank1 Info: | 2628850 |
| Area Total Sq Mi: | 1.34 |
| Area Land Sq Mi: | 1.34 |
| Area Water Sq Mi: | 0.00 |
| Population Density Sq Mi: | 126.39 |
Saint Onge (pronounced "saynt AHNJ'"[3]) is an unincorporated community and census-designated place (CDP) in Lawrence County, South Dakota, United States. As of the 2020 census, the population was 170.[4]
Saint Onge was laid out in 1881.[5] The community was named for Henry St. Onge, a pioneer settler.[6] A post office called Saint Onge has been in operation since 1881.[7] Saint Onge has been assigned the ZIP code of 57779.[8]
St. Onge is in northeastern Lawrence County, along South Dakota Highway 34, which leads northwest to Belle Fourche and southeast 7miles to Interstate 90 at Whitewood. Spearfish, the largest community in the county, is to the southwest.
According to the U.S. Census Bureau, the St. Onge CDP has an area of 3.5sqkm, all land.[9] False Bottom Creek forms the western edge of the community, and its tributary Dry Creek forms the northeastern edge. False Bottom Creek flows northwest to the Redwater River, which in turn is a tributary of the Belle Fourche River, flowing east to the Missouri.