Warm River
- County:
- Fremont County
- County Seat:
- No
- Area (mi²):
- 0.665
- State:
- Idaho
Warm River is a city located in Fremont County, Idaho. Warm River has a 2026 population of 1. Warm River is currently declining at a rate of 0% annually and its population has decreased by 0% since the most recent census, which recorded a population of 1 in 2020.