Achatinella mustelina is a species of air-breathing land snail, a terrestrial pulmonate gastropod mollusk in the family Achatinellidae. This species is endemic to the Waianae Range of the island of Oahu, Hawaii. All 13 subspecies of Achatinella mustelina were synonymized with the species by Holland & Hadfield (2007), because they are not monophyletic.