Onalaska
- County:
- Polk County
- County Seat:
- No
- Area (mi²):
- 5.437
- State:
- Texas
Onalaska is a city located in Polk County, Texas. Onalaska has a 2026 population of 3,367. Onalaska is currently growing at a rate of 4.18% annually and its population has increased by 9.28% since the most recent census, which recorded a population of 3,081 in 2020.