| Official Name: | Mount Vernon Township |
| Settlement Type: | Township |
| Image Map1: | Map of Illinois highlighting Jefferson County.svg |
| Mapsize1: | 150px |
| Map Caption1: | Jefferson County's location in Illinois |
| Subdivision Type: | Country |
| Subdivision Name: | United States |
| Subdivision Type1: | State |
| Subdivision Name1: | Illinois |
| Subdivision Type2: | County |
| Subdivision Name2: | Jefferson |
| Area Total Sq Mi: | 37.21 |
| Area Land Sq Mi: | 36.95 |
| Area Water Sq Mi: | 0.26 |
| Area Water Percent: | 0.70 |
| Population As Of: | 2010 |
| Population Density Sq Mi: | 362 |
| Elevation M: | 161 |
| Elevation Ft: | 528 |
| Coordinates: | 38.35°N -140°W |
| Timezone: | CST |
| Utc Offset: | -6 |
| Timezone Dst: | CDT |
| Utc Offset Dst: | -5 |
| Postal Code Type: | ZIP codes |
| Postal Code: | 62864, 62872 |
| Blank Name: | FIPS code |
| Blank Info: | 17-081-51193 |
| Pop Est As Of: | 2016 |
| Pop Est Footnotes: | [1] |
| Population Est: | 13216 |
| Unit Pref: | Imperial |
Mount Vernon Township is one of sixteen townships in Jefferson County, Illinois, USA. As of the 2010 census, its population was 13,374 and it contained 6,422 housing units.[2]
According to the 2010 census, the township has a total area of, of which (or 99.30%) is land and (or 0.70%) is water.[2] The township is centered at 38°21′N 88°52′W (38.349,-88.859). It is traversed north–south by State Route 37, east–west by State Route 15, and diagonally across its southwest corner by State Route 142.
(This list is based on USGS data and may include former settlements.)
The township contains these nine cemeteries: Atkinson, East Salem, Etheridge Farm, Hopewell, Oakwood, Old Union, Saint Mary's, Sursa and Williams.