Iguana is a herbivorous genus of lizard native to tropical areas of Mexico, Central America 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 endemic 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, there are also several other related genera in the same family for which the common name of the species includes the word "iguana".

The two species of lizard within the genus Iguana possess a dewlap, a row of spines running down their back to their tail, and a third "eye" on their head. This eye is known as the parietal eye, visible as a pale scale on the top of the head. Behind their neck are small scales which resemble spokes, known as tuberculate scales. These scales may be a variety of colors and are not always visible from close distances. They have a large round scale on their cheek known as a subtympanic shield.