Rock Rapids
- County:
- Lyon County
- County Seat:
- Yes
- Area (mi²):
- 4.213
- State:
- Iowa
Rock Rapids is a city located in Lyon County, Iowa. Rock Rapids has a 2026 population of 2,709. It is also the county seat of Lyon County. Rock Rapids is currently growing at a rate of 0.71% annually and its population has increased by 3.71% since the most recent census, which recorded a population of 2,612 in 2020.