Cydonius

Cydonius may refer to:


 * Demetrios Kydones (1324–1398), Byzantine theologian, translator, writer, and statesman
 * Prochorus Cydones (c. 1330–c.  1369), Eastern Orthodox monk, theologian, and linguist
 * Andreas Eudaemon-Joannis (1566–1625), Greek Jesuit, natural philosopher, and controversialist