Apocrypha (Greek apokryphos, “hidden”), word coined by the 5th-century biblical scholar St Jerome for the biblical books received by the Church of his time as part of the Greek version of the Old Testament (see Septuagint), but that were not included in the Hebrew Bible. In the Authorized, or King James, Version, the books are either printed as an appendix or are omitted altogether; they are not considered canonical by Protestants.

The Septuagint was received by the Christian Church from Hellenistic Judaism. The books included in the Septuagint that were excluded by the non-Hellenistic Jews from their canon were Judith, the Wisdom of Solomon, Tobit, Sirach (Ecclesiasticus), Baruch, and the two books of Maccabees. Of these, Judith and Tobit are best described as edifying historical fiction, and Baruch as an appendage to the Book of Jeremiah, written in the person of Jeremiah's secretary. Wisdom and Sirach are testimonies to the traditional wisdom of Israel otherwise represented in the books of Proverbs, Job, and Ecclesiastes. The books of Maccabees are historical works in the tradition of the books of Samuel, Kings, and Chronicles. Also generally included with the Apocrypha are the two books of Esdras, additions to the Book of Esther (Esther 10:4-10), the Song of the Three Young Men (Daniel 3:24-90), Susanna (Daniel 13), Bel and the Dragon (Daniel 14), and the Prayer of Manasseh.

Roman Catholic and Orthodox Christians still follow the Septuagint and include in the canon of the Bible all the Apocrypha, except the two books of Esdras and the Prayer of Manasseh. They generally refer to the Protestant Apocrypha as deuterocanonical books, however, and reserve the term Apocrypha for those books entirely outside the biblical canon, which Protestants call the pseudepigrapha.

With the growth of a historical perspective in biblical studies during the 19th century, the value of the Apocrypha as historical sources came to be generally recognized. Derived from the period 300 bc to New Testament times, the Apocrypha shed valuable light on the period between the end of the Old Testament narrative and the opening of the New Testament. They are also important sources of information on the development of belief in immortality, the resurrection, and other questions of eschatology, as well as the increasing impact of Hellenistic ideas on Judaism.

See also Bible.