John Day (or Daye) (c. 1522[1] – 23 July 1584) was an English Protestant printer. He specialised in printing and distributing Protestant literature and pamphlets, and produced many small-format religious books, such as ABCs, sermons, and translations of psalms. He found fame, however, as the publisher of John Foxe's Actes and Monuments, also known as the Book of Martyrs, the largest and most technologically accomplished book printed in sixteenth-century England.[2]