Polk Township is a township in Atchison County, Missouri, United States. At the 2020 census, its population was 211.
Polk Township was established in 1845 and was one of the five original townships in Atchison County. It was named after President James K. Polk.
Polk Township covers an area of and contains no incorporated settlements. It contains six cemeteries: High Creek, Linden, St. John's Lutheran, Grange Hall, Noblitt-gibson, and Steiner.
The streams of McElroy Creek, High Creek, West High Creek, and Hall Branch run through this township.