Catholic Bible vs Protestant Bible: Why Are They Different?

Why Catholic and Protestant Old Testaments differ by seven books

Open a Catholic Bible and a Protestant Bible to their tables of contents and the difference becomes clear in the Old Testament: the Catholic edition includes book titles a Protestant reader may never have encountered, such as Tobit, Judith, Wisdom, and Sirach. This is one of the most common questions Christians ask about Scripture, and it deserves a direct, practical answer.

This guide gives that answer plainly: exactly which books are involved, what each tradition calls them, why Catholics and Protestants share the same 27-book New Testament canon, and how the Old Testament difference developed without reducing the history to a slogan about one side simply adding or removing books. For the broader structure of Scripture before getting into this comparison, our complete guide to what the Bible is is the place to start.

The Numbers: 73 Books vs. 66 Books

The Catholic Bible contains 73 books in total: 46 in the Old Testament and 27 in the New Testament. The Protestant Bible contains 66 books: 39 in the Old Testament and the same 27 in the New Testament. The entire difference, in other words, comes down to a gap of exactly seven books in the Old Testament — plus a small number of additional passages within two books both traditions already share.

Both traditions share the same core Old Testament books, although Catholic and Protestant editions count and arrange that shared material within different canonical frameworks. The Catholic Old Testament includes seven additional full books, together with additional material in Esther and Daniel.

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Which Books Are Actually Different

The seven additional books found in Catholic Old Testaments, but not in Protestant ones, are: Tobit, Judith, Wisdom (sometimes called the Wisdom of Solomon), Sirach (also called Ecclesiasticus), Baruch (which includes a section called the Letter of Jeremiah), and 1 and 2 Maccabees. Beyond these seven full books, the Catholic Bible also includes additional passages within two books both traditions share: longer versions of Esther, with several extra sections woven throughout, and Daniel, with three added passages — the Prayer of Azariah and the Song of the Three Young Men, the story of Susanna, and the story of Bel and the Dragon.

Apart from these additional books and passages, Catholic and Protestant Old Testaments share the same major body of biblical books. Their editions can still differ in translation, textual basis, numbering, and arrangement, so “same books” should not be confused with word-for-word identical contents.

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Deuterocanonical vs. Apocrypha: Same Books, Different Names

The additional Catholic books and passages are often described with different terms because Catholic and Protestant traditions assign them different canonical status. Catholics commonly call them the deuterocanonical books, from Greek roots meaning “second canon.” The term does not mean “second-rate Scripture” or a lower level of inspiration. It is a later technical label used to distinguish books whose reception history was more disputed from books whose canonical status was less contested.

Protestant traditions commonly group these writings among the Apocrypha, although “Apocrypha” is not always an exact one-to-one label for the Catholic deuterocanonical collection: some Protestant Apocrypha sections have included additional texts as well. Early Protestant Bibles, including editions of the King James Version, often printed an Apocrypha section between the Testaments. Anglican and Lutheran traditions have also preserved forms of liturgical or devotional use without treating those books as equal in canonical authority to the 39-book Protestant Old Testament. A full account of what these books contain and why Christians classify them differently belongs in our dedicated guide to the Apocrypha and deuterocanonical books.

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Why the New Testament Is Identical in Both

This point deserves to be stated plainly, since it is easy to overlook amid discussion of Old Testament differences: Catholic and Protestant Bibles share the same 27-book New Testament canon — the same four Gospels, Acts, apostolic letters, and Revelation. Translations and textual choices can differ from edition to edition, but there is no Catholic-Protestant disagreement over which 27 books belong in the New Testament. By the time of the Reformation, that 27-book collection had long been established in Western Christianity, even though several New Testament books had been debated in earlier centuries. Our guide to the Old and New Testaments explains the broader structure in more depth.

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How This Difference Actually Came About

It is tempting to compress this history into a simple headline in either direction — “the Catholic Church added books” or “Protestants removed books” — and both versions miss important context. The books Catholics call deuterocanonical had circulated in ancient Greek Jewish Scripture and in Christian biblical collections long before the Reformation. Their history is closely connected with the Greek Septuagint tradition, although there was no single fixed ancient Septuagint volume with a universally agreed table of contents.

At the same time, these books did not enjoy completely uniform reception in every Christian community. Early and medieval writers sometimes distinguished among Old Testament books or debated particular texts. During the Reformation, Protestant reformers increasingly treated the books corresponding to the Jewish Hebrew canon as the normative Old Testament canon. Luther's German Bible, for example, still printed the additional books in a separate Apocrypha section rather than simply erasing them from Christian reading.

The Catholic Church responded to Reformation-era disputes by defining its canon at the Council of Trent in 1546. Trent's list did not appear without precedent: the same Catholic collection had been reflected in earlier Latin Christian practice and in earlier ecclesial lists, including the Council of Florence in 1442. The important point is therefore historical development, not a single dramatic moment of addition or subtraction. How Was the Biblical Canon Formed? follows that longer process from ancient Jewish Scripture through the early Church, regional lists, the Reformation, and Trent.

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A Brief Note on Orthodox Bibles

Catholic and Protestant Bibles are not the only patterns in wider Christian practice. Eastern Orthodox Old Testaments are often broader than the Catholic Old Testament, but there is no single book count that applies to every Orthodox church or edition. Greek Orthodox collections commonly include texts such as 3 Maccabees and Psalm 151, while the status or placement of other books can vary by tradition. It is therefore safer to speak of several Orthodox canonical traditions rather than one universally fixed “Orthodox Bible” that can be reduced to a single number.

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What This Means for Reading Either Bible

For a reader simply trying to identify the canon in a Bible, the practical takeaway is straightforward. If its Old Testament contains 39 books and omits Tobit, Judith, Wisdom, Sirach, Baruch, and 1–2 Maccabees as canonical books, it follows the standard Protestant canon. If it includes those seven books together with the Catholic forms of Esther and Daniel, it follows the Catholic canon. In both cases, the New Testament canon contains the same 27 books centered on the life, teaching, death, and resurrection of Jesus Christ.

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