Yellowbelly, the common name of a large number of fish of different species. In the United States the name is given to the red-breasted sunfish and to the beau gregory, which is found near coral reefs on the coasts of Florida and in the West Indies.

The red-breasted sunfish is Lepomis auritis of the sunfish family, Centrarchidae. The beau gregory is Eupomacentrus leucostictus of the damselfish family, Pomacentridae.