The Protestant Old Testament is identical to the Hebrew Bible, though the books are arranged and divided differently.

Roman Catholics since 1546 (the Council of Trent) have officially included the "deutero-canonical" or "apocryphal" books. These books were included in early editions of the King James Bible, but Protestants have not considered them authoritative because they are not found in the Hebrew Bible.

Hebrew Bible

Protestant Bible

Roman Catholic Bible

24 books

39 books

46 books
(The Protestant List, plus:)

The Law

Law

Genesis

Genesis

Exodus

Exodus

Leviticus

Leviticus

Tobit

Numbers

Numbers

Judith

Deuteronomy

Deuteronomy

Wisdom of Solomon

Ecclesiasticus (Sirach)

The Prophets

History

Baruch (includes the Letter of
Jeremiah)

Joshua

Joshua

I & II Maccabees

Judges

Judges

Samuel

Ruth

Additions to Daniel:

Kings

I & II Samuel

Song of the Three Young Men

Isaiah

I & II Kings

Susanna

Jeremiah

I & II Chronicles

Bel and the Dragon

Ezekiel

Ezra

Minor Prophets

Nehemiah

Additions to Esther

Esther

The Writings

Psalms

Poetry and Wisdom

Proverbs

Job

Job

Psalms

Song of Solomon

Proverbs

Ruth

Ecclesiastes

Lamentations

Song of Solomon

Ecclesiastes

Esther

Prophecy

Daniel

Isaiah

Ezra-Nehemiah

Jeremiah

Chronicles

Lamentations

Ezekiel

Daniel

The 12 Minor Prophets