We describe Gekko pradapdao sp. nov. from Tham Khao Chan (Khao Chan Cave), Tha Luang District, Lopburi Province, in central Thailand. The new species, a member of the subgenus Gekko, differs from all currently recognized Gekko species by the following combination of morphological characters and pattern: maximal known snout-vent length of 127.1 mm, lack of contact between nostrils and rostral, 2428 interorbital scales between supraciliaries, 8991 scale rows around midbody, 1618 dorsal tubercle rows at midbody, 3034 ventral scale rows at midbody, 1113 precloacal pores in males, a single postcloacal tubercle on each side of the base of the tail, 1316 subdigital lamellae on 1st toe and 1719 on 4th toe, no Y-shaped mark on head, non-banded dorsal pattern on a dark chocolate brown to black background, and a dark brown iris. Urgent actions should be taken to evaluate the conservation status of the new species.