Hyposmocoma mediella is a species of moth of the family Cosmopterigidae. It was first described by Lord Walsingham in 1907. It is endemic to the Hawaiian island of Oahu. The type locality is the Waianae Range.
. Elwood Zimmerman . 1978 . Insects of Hawaii . 9 Microlepidoptera . The University Press of Hawaii, Honolulu. 10125/7338 .