Ecsenius trilineatus, known commonly as the Three-lined blenny in Australia, and the White-spotted comb-tooth or the White-spotted combtooth blenny in Indonesia, is a species of combtooth blenny in the genus Ecsenius. It is a non-migoratory species of blenny found in coral reefs in the western central Pacific ocean. It can reach a maximum length of 3 centimetres. Blennies in this species feed primarily off of plants, including benthic algae and weeds, and are commercial aquarium fish, but of no interest in fisheries.