| Place Name | Underwood-Petersville |
| Place Type | Census Designated Place |
| ZIP Code(s) | 35630 35633 |
| County | Lauderdale County |
| Area Code(s) | 256,938 |
| Timezone | Central Daylight Time (CDT) |
| Population (2022) | 3,325 |
| Population Growth Rate (2010-19) | -6.04% |
| Majority Ethnicity | White 93.1% |
| Metro/Micro Stats Area | Florence-Muscle Shoals, AL |
| US Congressional District(s) | Alabama 5th |
| State House Districts | 1,2 |
| State Senate Districts | 1 |
| Race/Ethnicy | Percentage of Population (2021) |
|---|---|
| White | 93.1% |
| African American | 4.09% |
| Hispanic | 0% |
| Asian | 0% |
| Native American | 0% |
| Hawaiin/Pacific Islander | 2.81% |