Cosmopterix attenuatella is a moth of the family Cosmopterigidae. It is widely distributed in the tropics and subtropics of both the Old and New World, including the United States, Bermuda, the Cayman Islands, Virgin Islands, Dominica, Jamaica, Puerto Rico, Trinidad and Tobago, Costa Rica, Brazil, Ecuador, Peru, Argentina, the Canary Islands, Madeira, the Galapagos Islands, Cook Islands, Taiwan, Australia, New Zealand, Madagascar, Seychelles, Mauritius and Saint Helena.