Twin Lake Township is one of sixteen townships in Hancock County, Iowa, USA. As of the 2000 census, its population was 197.
Twin Lake Township was organized in 1882. It was named from two lakes in the southern part of the township.
According to the United States Census Bureau, Twin Lake Township covers an area of 35.77 square miles (92.64 square kilometers); of this, 35.32 square miles (91.48 square kilometers, 98.75 percent) is land and 0.45 square miles (1.16 square kilometers, 1.25 percent) is water.