Ecsenius mandibularis, known commonly as the Queensland blenny in Australia, is a species of combtooth blenny in the genus Ecsenius. It is found in coral reefs in the western Pacific ocean, including the southern edge of the Great Barrier Reef. It can reach a maximum length of 7.5 centimetres. Blennies in this species feed primarily off of plants, including benthic algae and weeds.