Chameleons occur naturally only in the Old World. Africa (including offshore islands) has the highest concentration of species and subspecies, with all 27 members of the genus Bradypodion, all 14 forms in the genus Rhampholeon, and 59 forms in the genus Chamaeleo, totaling 99 species and subspecies. Forty percent of the world's species inhabit Madagascar and offshore islands, including 19 of the 21 members of the genus Furcifer, all 27 forms in the genus Brookesia, and 28 forms in the genus Calumma, for a total of 73 species and subspecies. The eight remaining forms are from Yemen (one),
Saudi Arabia (two), India and Sri Lanka (one), the Comoro Islands (two), Socotra (one), and the Seychelles (one).
One species, Chamaeleo chamaeleon, or the common chameleon, is found in Europe, the Middle East, Greece, northern Africa, southwestern Saudi Arabia, and Yemen. This makes up the widest range of distribution of any chameleon species. Jackson's chameleon (Chamaeleo jacksonii) has the dubious distinction of being the first chameleon species to be introduced and become well established in the New World. A few dozen specimens imported for the pet trade in the 1970s escaped into the wilderness in Hawaii, creating a large feral population that has continued to thrive more than 30 years later.