Diamond Lake Township is one of twelve townships in Dickinson County, Iowa, United States.

As of the 2000 census, its population was 296.

[1] According to the United States Census Bureau, Diamond Lake Township covers an area of 28.79 square miles (74.58 square kilometers); of this, 28.26 square miles (73.19 square kilometers, 98.14 percent) is land and 0.53 square miles (1.38 square kilometers, 1.85 percent) is water.

(This list is based on USGS data and may include former settlements.)