The Town of Janesville is a located in Rock County, Wisconsin, United States.

The City of Janesville is located to the southeast of and adjacent to the town.

The unincorporated communities of Anderson and Leyden are located in the town.

As of the census[2] of 2000, there were 3,750 people, 1,137 households, and 908 families residing in the town.

15.3% of all households were made up of individuals, and 4.7% had someone living alone who was 65 years of age or older.