Ivan Fyodorov was a 16th-century deacon and a pioneering figure in Eastern Slavonic printing. Born in the Grand Principality of Moscow, he later moved to the Polish–Lithuanian Commonwealth, where he worked in Zabłudów, Ostroh, and Lviv. He is celebrated for his technical contributions to typography, including the publication of the landmark Ostrog Bible in 1581. Beyond his work with moveable type, he was a skilled cannon maker who invented a multibarreled mortar. He is recognized as a saint in certain traditions.