As of the 2020 census, its population was 2,275 (up from 2,162 at 2010[4]) and it contained 1,648 housing units.

[5] According to the 2010 census, the township has a total area of 31.7 square miles (82 km2), of which 30.67 square miles (79.4 km2) (or 96.75%) is land and 1.03 square miles (2.7 km2) (or 3.25%) is water.

[4] (This list is based on USGS data and may include former settlements.)

The township contains two cemeteries: Schock and Yeoman.

Jefferson Township residents may obtain a library card at the Delphi Public Library in Delphi.