Onalaska is a town in La Crosse County, Wisconsin, United States. The population was 5,623 at the 2010 census. The City of Onalaska borders the town, as does the village of Holmen. The CDP of Brice Prairie is located in the western part of the Town of Onalaska. The unincorporated community of Midway is also located in the town. Onalaska (town), Wisconsin is part of the La Crosse, Wisconsin Metropolitan Statistical Area.

La Crosse County is a county located in the U.S. state of Wisconsin. At the 2020 census, the population was 120,784. Its county seat is La Crosse. La Crosse County is included in the La Crosse-Onalaska, WI-MN Metropolitan Statistical Area with a population of 139,627 and is the most populous county on Wisconsin's western border.