McLachlan's girdled lizard (Cordylus mclachlani), also known commonly as McLachlan's spiny-tailed lizard, is a species of lizard in the family Cordylidae. The species is endemic to South Africa.
The specific name, mclachlani, is in honor of South African herpetologist Geoffrey Roy McLachlan.
Adults of Cordylus mclachlani usually have a snout-to-vent length (SVL) of . The body is very flattened. Dorsally, it is olive brown, with some dark brown and yellow spots. Ventrally, it is cream-colored.
Cordylus mclachlani is found in the South African provinces of Northern Cape and Western Cape.
The preferred natural habitat of Cordylus mclachlani is rocky areas of shrubland.
Cordylus mclachlani is terrestrial and rupicolous (rock-dwelling), sheltering in narrow crevices.
Cordylus mclachlani is ovoviviparous.