Microlophus grayii, also commonly known as the Floreana lava lizard, Gray's lava lizard, and Gray's Pacific iguana, is a species of lava lizard in the family Tropiduridae.

The species is endemic to the Galapagos island of Floreana.

[2] The specific name, grayii, is in honor of British herpetologist John Edward Gray.

[4] M. grayii is found on Floreana Island including its islets Champion and Gardner, in the Galapagos, Ecuador.

[1] The preferred natural habitat of M. grayii is shrubland, at altitudes from sea level to 640 m (2,100 ft), but it has also been found in urban areas.