The native territory of the longear sunfish, Lepomis megalotis, is exclusive to North America; it is found primarily in the Mississippi and Great Lakes watersheds. The species ranges from Minnesota east to Ontario, Ohio, and western Pennsylvania southward through the Mississippi Basin to the Gulf states of Mexico and east to the Apalachiocola River.
Longear sunfish, like other members of the sunfish family Centrarchidae, are freshwater fishes. In the warmer months of spawning season longear sunfish are generally found in shallower, warmer headwaters of streams which have numerous pools with permanent or semi-permanent flow. They prefer waters with a hard bottom of clay or gravel with clear waters and usually in or near aquatic vegetation. Although more abundant in headwaters, they can be found in streams and rivers of all sizes and are also found in lakes. Compared to other members of the sunfish family Centrarchidae, longear sunfish are better at obtaining food in moving waters than still waters