| Place Name | Mill Plain |
| Place Type | Census Designated Place |
| ZIP Code(s) | 06824 06890 |
| County | Fairfield County |
| Area Code(s) | 203,475 |
| Timezone | Eastern Standard Time (EST) |
| Population (2022) | 1,678 |
| Majority Ethnicity | White 93.9% |
| Metro/Micro Stats Area | Bridgeport-Stamford-Norwalk, CT |
| US Congressional District(s) | Connecticut 4th |
| State House Districts | 132 |
| State Senate Districts | 28 |
| Race/Ethnicy | Percentage of Population (2021) |
|---|---|
| White | 93.9% |
| African American | 0% |
| Hispanic | 0% |
| Asian | 0.62% |
| Native American | 0% |
| Hawaiin/Pacific Islander | 5.48% |