Thiotricha oleariae is a moth of the family Gelechiidae. It was described by George Hudson in 1928. It is found in New Zealand, where it has been recorded from the central part of the North Island south to Stewart Island. Adults are grey with darker markings. The larvae feed on the foliage of Olearia species, including Olearia solandri from within a portable case. They mine and erode the leaves.