The smallmouth bass (Micropterus dolomieu) is a species of freshwater fish in the sunfish family (Centrarchidae) of the order Perciformes. It is the type species of its genus.
One of the black basses, it is a popular game fish sought by anglers throughout the temperate zones of North America, and has been spread by stock to many cool-water tributaries and lakes in Canada and more so introduced in the United States.
The smallmouth bass is native to the upper and middle Mississippi River basin, the Saint Lawrence River–Great Lakes system, and up into the Hudson Bay basin. Its common names include smallmouth, bronzeback, brown bass, brownie, smallie, bronze bass, and bareback bass.