| Place Name | Marissa Township |
| Place Type | Township |
| ZIP Code(s) | 62255 62257 |
| County | Saint Clair County |
| Area Code(s) | 618 |
| Timezone | Central Daylight Time (CDT) |
| Population (2021) | 1,643 |
| Majority Ethnicity | White 98.24% |
| Metro/Micro Stats Area | St. Louis, MO-IL |
| US Congressional District(s) | Illinois 12th |
| State House Districts | 116 |
| State Senate Districts | 58 |
| Race/Ethnicy | Percentage of Population (2021) |
|---|---|
| White | 98.24% |
| African American | 0% |
| Hispanic | 0% |
| Asian | 0% |
| Native American | 0% |
| Hawaiin/Pacific Islander | 1.76% |