The bullfrog is native to eastern North America. Its natural range extends from the Atlantic Coast to as far west as Oklahoma and Kansas.
Other countries into which the bullfrog has been introduced include Mexico, the western half of Canada, Cuba, Jamaica, Italy, the Netherlands, and France. The reasons for introducing the bullfrog to these countries have included their intentional release, either to provide a source of food or as biological control agents, the escape of frogs from breeding establishments, and the escape or release of frogs kept as pets. Conservationists are concerned the bullfrog is relatively immune to the fungal infection chytridiomycosis and as it invades new territories, it may assist the spread of this lethal disease to more susceptible native species of frog.