Smithfield Township is one of twenty townships in Fayette County, Iowa, USA. As of the 2010 census, its population was 250.GeographyAccording to the United States Census Bureau, Smithfield Township covers an area of 36.09 square miles (93.47 square kilometers).Adjacent townships Westfield Township (north) Illyria Township (northeast) Fairfield Township (east) Putnam Township (southeast) Scott Township (south) Jefferson Township (southwest) Harlan Township (west) Center Township (northwest)CemeteriesThe township contains Garden Prairie Cemetery.Major highways 25px Iowa Highway 150 25px Iowa Highway 187