| Place Name | Petersham |
| Place Type | Census Designated Place |
| ZIP Code(s) | 01366 |
| County | Worcester County |
| Area Code(s) | 351,978 |
| Timezone | Eastern Daylight Time (EDT) |
| Population (2022) | 303 |
| Population Growth Rate (2010-19) | -7.41% |
| Majority Ethnicity | White 86.81% |
| Metro/Micro Stats Area | Worcester, MA-CT |
| US Congressional District(s) | Massachusetts 2nd |
| State House Districts | 2nd Franklin |
| State Senate Districts | Worcester, Hampden, Hampshire and Middlesex |
| Race/Ethnicy | Percentage of Population (2021) |
|---|---|
| White | 86.81% |
| African American | 1.83% |
| Hispanic | 0% |
| Asian | 0% |
| Native American | 0% |
| Hawaiin/Pacific Islander | 11.36% |