| Place Name | Marble Rock |
| Place Type | City |
| ZIP Code(s) | 50653 |
| GEOID | 1949305 |
| County | Floyd County |
| Area Code(s) | 641 |
| Timezone | Central Daylight Time (CDT) |
| Population (2021) | 306 |
| Population Growth Rate (2010-19) | -11.73% |
| Majority Ethnicity | White 99.66% |
| US Congressional District(s) | Iowa 4th |
| State House Districts | 52 |
| State Senate Districts | 26 |
| Race/Ethnicy | Percentage of Population (2021) |
|---|---|
| White | 99.66% |
| African American | 0% |
| Hispanic | 0% |
| Asian | 0% |
| Native American | 0% |
| Hawaiin/Pacific Islander | 0.34% |