The Catechism on Sacred Scripture - Section 120

IV. THE CANON OF SCRIPTURE
 
120 It was by the apostolic Tradition that the Church discerned which writings are to be included in the list of the sacred books.⁹⁰ This complete list is called the canon of Scripture. It includes 46 books for the Old Testament (45 if we count Jeremiah and Lamentations as one) and 27 for the New.⁹¹
 
The Old Testament: Genesis, Exodus, Leviticus, Numbers, Deuteronomy, Joshua, Judges, Ruth, 1 and 2 Samuel, 1 and 2 Kings, 1 and 2 Chronicles, Ezra and Nehemiah, Tobit, Judith, Esther, 1 and 2 Maccabees, Job, Psalms, Proverbs, Ecclesiastes, the Song of Songs, the Wisdom of Solomon, Sirach (Ecclesiasticus), Isaiah, Jeremiah, Lamentations, Baruch, Ezekiel, Daniel, Hosea, Joel, Amos, Obadiah, Jonah, Micah, Nahum, Habakkuk, Zephaniah, Haggai, Zachariah and Malachi. 

The New Testament: the Gospels according to Matthew, Mark, Luke and John, the Acts of the Apostles, the Letters of St. Paul to the Romans, 1 and 2 Corinthians, Galatians, Ephesians, Philippians, Colossians, 1 and 2 Thessalonians, 1 and 2 Timothy, Titus, Philemon, the Letter to the Hebrews, the Letters of James, 1 and 2 Peter, 1, 2 and 3 John, and Jude, and Revelation (the Apocalypse).

90 Cf. DV 8 § 3.
91 Cf. DS 179; 1334-1336; 1501-1504.

Source: Catechism of the Catholic Church