Sphaerodactylus ariasae, commonly called the Jaragua sphaero or the Jaragua dwarf gecko, is the smallest species of lizard in the family Sphaerodactylidae.

The second-smallest is S. parthenopion, native to the British Virgin Islands.

The Jaragua sphaero measures 14–18 mm (0.55–0.71 in)[3] from the snout to the base of the tail and can fit on a US 25-cent coin.

[citation needed] The geographic range of S. ariasae is believed to be limited to Jaragua National Park, in the southernmost tip of the Barahona Peninsula, in the extreme southwest of the Dominican Republic and nearby forested Beata Island on Hispaniola.

[4] S. ariasae was first described by Blair Hedges, a Pennsylvania State University evolutionary biologist, and Richard Thomas, a University of Puerto Rico biologist, in the December 2001 issue of the Caribbean Journal of Science.