| Place Name | Merrimac |
| Place Type | Town |
| ZIP Code(s) | 01860 |
| County | Essex County |
| Area Code(s) | 351,978 |
| Timezone | Eastern Standard Time (EST) |
| Population (2021) | 6,698 |
| Majority Ethnicity | White 97.35% |
| Metro/Micro Stats Area | Boston-Cambridge-Newton, MA-NH |
| US Congressional District(s) | Massachusetts 6th |
| State House Districts | 2nd Essex |
| State Senate Districts | First Essex |
| Race/Ethnicy | Percentage of Population (2021) |
|---|---|
| White | 97.35% |
| African American | 0% |
| Hispanic | 0% |
| Asian | 1.16% |
| Native American | 0% |
| Hawaiin/Pacific Islander | 1.49% |