Iguana is a genus of herbivorous lizards native to tropical areas of Mexico, Central America, several islands in Polynesia such as Fiji and Tonga, and the Caribbean. The genus was first described in 1768 by Austrian naturalist Josephus Nicolaus Laurenti in his book Specimen Medicum, Exhibens Synopsin Reptilium Emendatam cum Experimentis circa Venena. Two species are included in the genus Iguana: the green iguana, which is widespread throughout its range and a popular pet, and the Lesser Antillean iguana, which is native to the Lesser Antilles and endangered due to habitat destruction.

The word "iguana" is derived from a Spanish form of the original Taino name for the species, iwana.

In addition to the two species in the genus Iguana, several other related genera in the same family have common names of the species including the word "iguana".