The dog was spotted floating down Los Angeles River in Burbank following thunderstorms on January 30.
To carry out the rescue, a firefighter was lowered from a helicopter into the river near the Cahuenga Pass. He then swam towards the Corgi/Chihuahua mix, and caught it in his arms, before lifting it to safety.
The seven-year-old dog did not have a tag or microchip but authorities believe the canine has an owner, as it had a collar and leash.
The dog was taken to North Central Animal Shelter in Lincoln Heights where it is recovering.