What are the deuterocanonical books included in Catholic Old Testament?

1. What the Catholic Church officially includes: the canonical list

The Catholic canon of the Old Testament comprises the thirty-nine protocanonical books accepted in the Hebrew Bible plus seven deuterocanonical books—Tobit, Judith, Wisdom (of Solomon), Sirach (Ecclesiasticus), Baruch (including the Letter of Jeremiah), 1 Maccabees, and 2 Maccabees—and also recognizes additions to Esther and Daniel such as the Prayer of Manasseh and the longer Daniel passages ^{[1] [2] [3]}.

2. The “seven” versus the longer lists: what counts as a deuterocanonical book

Most Catholic teaching and reference works highlight seven full books as the core deuterocanonical set (the seven listed above) while also treating several additions to Esther and Daniel as deuterocanonical material—so Catholics speak of a total Old Testament of 46 books where the seven are the principal extra books beyond the Hebrew canon ^{[1] [6]}. Broader historical inventories and Eastern traditions sometimes list additional works (e.g., 3–4 Maccabees, 1–2 Esdras, Prayer of Manasseh) as deuterocanonical or anagignoskomena, but Rome’s normative list centers on the seven plus the Esther/Daniel additions ^{[2] [7]}.

3. Why these books are “deuterocanonical” and not “protocanonical”

The label “deuterocanonical” (literally “second canon”) reflects that their canonicity was disputed or confirmed later in the Western tradition; Catholics trace acceptance in regional councils from the fourth century and a definitive affirmation at the Council of Trent in the sixteenth century, which accepted the books in the Latin Vulgate as canonical ^{[4] [5] [1]}. The term itself and its nuance have evolved: some authors use it to indicate later confirmation, others to signal secondary authority compared with protocanonical books ^[4].

4. Protestant and Reform-era challenges: removal and the term “Apocrypha”

During the Reformation, Protestants generally removed the deuterocanonical books from the canonical Old Testament and labeled them “Apocrypha,” partly because they were not in the Hebrew Masoretic text and because some Reformers argued they supported doctrines they rejected—most famously Martin Luther’s relegation of these books to an appendix in his Bible ^{[8] [1]}. Protestant reference works therefore often list only thirty-nine Old Testament books, treating the deuterocanonical texts as useful but non‑canonical ^{[1] [9]}.

5. Eastern Orthodox and other traditions: larger and regionally variable canons

Eastern Orthodox churches traditionally accept the deuterocanonical books and in many cases include additional Septuagint books beyond Rome’s seven; Eastern practice often uses the Greek term anagignoskomena (“readable”) and manifests regional differences in which extra texts are liturgically read and given authority ^{[4] [10] [7]}. Scholars emphasize that the Septuagint-based canons used by many early Christians made the status of some books fluid across time and place ^{[7] [11]}.

6. How these books are used in Catholic life and the limits of reporting

In Catholic liturgy, lectionary readings and theological teaching draw on deuterocanonical material—examples cited include Tobit and 2 Maccabees passages used to support doctrines such as almsgiving and prayer for the dead—while apologetic and devotional literature defends their theological value and historical role in the biblical tradition ^{[3] [8] [5]}. The sources provided summarize canonical lists, historical councils, and inter‑denominational disagreement, but they do not exhaust manuscript evidence or the full patristic debates; further primary‑source study (council acts, Vulgate manuscripts, Septuagint witnesses) would be required for a comprehensive historical reconstruction ^{[4] [11]}.