Crystal Township is one of sixteen townships in Hancock County, Iowa, USA.

As of the 2000 census, its population was 529.

[1] Crystal Township was founded in 1869.

[2] The township was named from Crystal Lake.

[3] According to the United States Census Bureau, Crystal Township covers an area of 35.5 square miles (91.96 square kilometers); of this, 35.11 square miles (90.93 square kilometers, 98.88 percent) is land and 0.4 square miles (1.03 square kilometers, 1.12 percent) is water.