Mount Vernon Township is one of sixteen townships in Jefferson County, Illinois, United States.

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 37.21 square miles (96.4 km2), of which 36.95 square miles (95.7 km2) (or 99.30%) is land and 0.26 square miles (0.67 km2) (or 0.70%) is water.

(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.