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

As of the 2010 census, its population was 871.

[1] According to the United States Census Bureau, Harlan Township covers an area of 36.79 square miles (95.28 square kilometers); of this, 36.76 square miles (95.22 square kilometers, 99.94 percent) is land and 0.03 square miles (0.07 square kilometers, 0.07 percent) is water.

The township contains these two cemeteries: Hope and Long Grove.