| Official Name: | Irwin, Missouri |
| Settlement Type: | Census-designated place & unincorporated community |
| Mapsize: | 250px |
| Pushpin Map: | Missouri |
| Pushpin Label: | Irwin |
| Pushpin Label Position: | bottom |
| Subdivision Type: | Country |
| Subdivision Name: | United States |
| Subdivision Type1: | State |
| Subdivision Name1: | Missouri |
| Subdivision Type2: | Counties |
| Subdivision Name2: | Barton |
| Subdivision Type3: | Township |
| Unit Pref: | Imperial |
| Area Footnotes: | [1] |
| Area Total Km2: | 0.78 |
| Area Land Km2: | 0.77 |
| Area Water Km2: | 0.02 |
| Area Total Sq Mi: | 0.30 |
| Area Land Sq Mi: | 0.30 |
| Area Water Sq Mi: | 0.01 |
| Population As Of: | 2020 |
| Population Total: | 47 |
| Population Density Km2: | 61.26 |
| Population Density Sq Mi: | 158.78 |
| Timezone: | Central (CST) |
| Utc Offset: | -6 |
| Timezone Dst: | CDT |
| Utc Offset Dst: | -5 |
| Elevation Ft: | 968 |
| Coordinates: | 37.5886°N -94.2872°W |
| Postal Code Type: | ZIP code |
| Postal Code: | 64759 |
| Area Code: | 417 |
| Blank Name: | FIPS code |
| Blank Info: | 29-35486[2] |
| Blank1 Name: | GNIS feature ID |
| Blank1 Info: | 2587082 |
Irwin is an unincorporated community and census-designated place in northern Barton County, Missouri, United States. As of the 2020 census it had a population of 47.[3]
Irwin was platted in 1884.[4] The community has the name of the Irwin family of settlers.[5] A post office called Irwin was established in 1884, and remained in operation until 1981.[6]
Irwin is located halfway between Lamar and Sheldon on U.S. Route 71 (Interstate 49).
According to the United States Census Bureau, the CDP has a total area of 0.78sqkm, of which 0.02sqkm, or 2.00%, is water.[7]