A new species of trapdoor spider of the genus Liphistius Schiödte, 1849 (Mesothelae: Liphistiidae) is described from specimens collected from Mae Wong National Park, Klonglan district, Kamphaeng Phet province, Thailand. This Liphistius species belongs to the bristowei species-group based on the elevated cumulus and the distinct embolic part, and resembles L. yamasakii Ono, 1988. Diagnostic characters of the male and female are discussed, and a map is provided for the type localities of the 32 previously described Liphistius species in Thailand. This is the first record of a Liphistius species in the bristowei species-group that builds a T- or Y-shaped burrow with two trapdoor openings.