The false trevally (Lactarius lactarius) is a species of fish in the family Lactariidae, currently the sole member of the family.
The false trevally is native to the Indian Ocean and from East Africa to Southeast Asia, and in the western Pacific Ocean from Japan to Queensland, Australia. It is a coastal species, occurring in marine and brackish waters at depths of from . It is an important species to local commercial fisheries.
This fish is colored silvery-grey on the upper parts with blue iridescence dorsally and a dusky black spot on the upper gill cover. The underparts are colored silvery-white. The fins are pale yellow. This species can reach a length of, though most do not exceed .