Jefferson Township is one of twenty townships in Fayette County, Iowa, USA.

As of the 2010 census, its population was 6,910.

[1] According to the United States Census Bureau, Jefferson Township covers an area of 36.46 square miles (94.42 square kilometers); of this, 36.37 square miles (94.2 square kilometers, 99.77 percent) is land and 0.09 square miles (0.22 square kilometers, 0.23 percent) is water.

The township contains these three cemeteries: Oakdale, Otsego and Woodlawn.