Conchylodes diphteralis is a moth in the Crambidae family. It was described by Geyer in 1832. It is found from the south-eastern United States, where it has been recorded from Florida, through the West Indies (including Cuba, Jamaica and Hispaniola) to South America. The wingspan is 24–29 mm. Adults are on wing nearly year round in Florida. The larvae feed on Cordia species.