Castle Rock is a town in Grant County, Wisconsin, United States.

The unincorporated community of Castle Rock is located in the town.

According to the United States Census Bureau, the town has a total area of 35.8 square miles (92.7 km2), all of it land.

At the 2000 census there were 314 people, 112 households, and 86 families living in the town.

There were 122 housing units at an average density of 3.4 per square mile (1.3/km2).