The Catholic Church (and most Orthodox Churches) have at least seven books in their Old Testament which Protestant Bibles do not: Sirach, Tobit, Wisdom, Judith, 1 and 2 Maccabees, and Baruch. Catholics refer to them as the deuterocanonical ("second canon") books because they were originally disputed and their canonicity established later than other books. Protestants say that they are not inspired and so call them "Apocrypha."
The Catholic Church first established the complete list of books at the Council of Rome in 382, which included the deuterocanonical books. It has reaffirmed that same list many times throughout history, especially during times when some disputed the canon. While Protestants may claim that the Catholic and Orthodox Churches each added these books much later in history, or even as late as the Protestant Reformation, this is not the case.
Ironically, to justify the set of books in Protestant Bibles, Protestants must agree with the Council of Rome's New Testament canon, but reject the same council's Old Testament canon. In addition, they must accept the Jewish Council of Jamnia's views on the Old Testament canon, and ignore the fact that this same council is the one where the Gospels were rejected as Jewish scripture.
- 5 Myths about 7 Books - Answers to five false claims about the deuterocanonicals; by Jason Evert (catholic.com)
- How to Defend the Deuterocanonicals - Answers to common questions; by Jason Evert (catholic.com)
- Counting the Canon - A historical viewpoint; by Steven L. Kellmeyer
- Did the Catholic Church Add to the Old Testament? - Presented as a two-person conversation; by Kenneth J. Howell (catholic.com)
- The Council That Wasn’t - Examines the Council of Jabneh and the Old Testament canon; by Steve Ray (catholic.com)
- Saving Judith and Tobit - Looks at common criticisms of these two books; by Jimmy Akin (catholic.com)
- Why do Catholics have 7 more books in their bible? Part 1 [7 min] - A brief history; by ithcus777
- Why do Catholics have 7 more books in their bible? Part 2 [8 min] - Answers to common objections to the deuterocanonical books; By ithcus777
- Deuterocanonical References in the New Testament - An exhaustive list; by Jimmy Akin
- Deuterocanonical Books in the New Testament - Shows the deuterocanonicals quoted by the New Testament and by the early Church Fathers (scripturecatholic.com)
- Septuagint in the New Testament - Shows the New Testament writers quoting the Septuagint (Greek) version of the Old Testament which includes the deuterocanonicals, and not the Hebrew version. Note the slight language differences (scripturecatholic.com)
- Old Testament Canon - Nihil Obstat and Imprimatur - Quotes from the deuterocanonical books by the early Church Fathers (catholic.com)
- Four Hundred Silent Years? - Was there really a 400-year gap between writing the Old and New Testaments? By Jimmy Akin (catholic.com)