Demetri Porphyrios (Greek: Δημήτρης Πορφυρίου; born 1949) is a Greek architect and author who practices architecture in London as principal of the firm Porphyrios Associates. In addition to his architectural practice and writing, Porphyrios has held a number of teaching positions in the United States, the United Kingdom and Greece. He is currently a visiting professor at the Yale School of Architecture. While Porphyrios is considered to be an exponent of New Classical Architecture, he has designed buildings in both the Gothic and Classical idioms.