Hyposmocoma lignivora is a species of moth of the Cosmopterigidae family. It is endemic to Oahu and Molokai. This is a common and widely distributed moth on Oahu. This was the first endemic species of Hawaiian Microlepidoptera to be described. The larvae are common in rotten wood and under dead bark of various trees, native and introduced, including Pisonia, Tetraplasandra and Wikstroemia. True lignivora appears to occur on Oahu and Molokai, but associated distinct forms evidently also occur on Molokai and perhaps on Oahu.