Jefferson Township, Sullivan County, Indiana
Jefferson Township is one of nine townships in Sullivan County, Indiana, United States. At the 2010 census, its population was 417 and it contained 234 housing units.

Geography
According to the 2010 census, the township has a total area of , of which  (or 98.77%) is land and  (or 1.23%) is water.

Unincorporated towns
 Bucktown at 
 Pleasantville at 
(This list is based on USGS data and may include former settlements.)

Adjacent townships
 Cass Township (north)
 Stockton Township, Greene County (northeast)
 Stafford Township, Greene County (east)
 Vigo Township, Knox County (south)
 Widner Township, Knox County (southwest)
 Haddon Township (west)

Cemeteries
The township contains six cemeteries: Hale, McDade, Pirtle, Posey, Smith and Woodward.

Lakes
 Motorboat Lake
 Red Lake
 South Lake
 T Lake
 Twin Lake

School districts
 Northeast School Corporation

Political districts
 Indiana's 8th congressional district
 State House District 45
 State Senate District 39