Warm River is a city in Fremont County, Idaho, United States.

[5] It is part of the Rexburg, Idaho Micropolitan Statistical Area.

Warm River was incorporated in the 1940s in order to bring the small resort community in compliance with state law restricting liquor licenses to only incorporated municipalities.

50.0% of all households were made up of individuals, and 50% had someone living alone who was 65 years of age or older.

In the city, the population was spread out, with 30.0% from 18 to 24, 20.0% from 25 to 44, 10.0% from 45 to 64, and 40.0% who were 65 years of age or older.