Sphaerodactylus williamsi, also known commonly as Williams's least gecko or the Haitian striped geckolet, is a small species of lizard in the family Sphaerodactylidae.

[2] The specific name, williamsi, is in honor of American herpetologist Ernest Edward Williams.

[3] The preferred habitat of S. williamsi is forest.

The holotype has a snout-to-vent length (SVL) of 22 mm (0.87 in).

It has small keeled dorsal scales.