Janesville is a city located in Bremer County, in the state of Iowa (IA), United States. Nestled in the West North Central division of the Midwest region, it covers an area of 1.5 square miles (4.0 km²) and sits at an elevation of 910 ft. With a population of approximately 829 residents, Janesville offers a peaceful, rural atmosphere.
The town's population is composed of about 50.18% males and 49.82% females, and it has a population density of 571.72 people per square mile (220.74/km²). Janesville lies at a latitude of 42.65 and a longitude of -92.46, operating in the UTC-6.
Locals reflect a blend of American ancestry, with roots primarily in United States (11.9%), followed by English (9.2%), German (46.8%), and Scotch-Irish (0%) heritage. The town is identified by the ZIP code 50647.