Yes, the Old Testament in the Catholic Bible is largely derived from the Tanakh (the Hebrew Bible). However, there are some important differences:
* Inclusion of Deuterocanonical Books: The Catholic Old Testament includes seven books and portions of two others that are not included in the Tanakh or the Protestant Old Testament. These are known as the deuterocanonical books (or apocryphal books in Protestant tradition). They are: Tobit, Judith, Baruch, 1 and 2 Maccabees, Wisdom, Sirach, and portions of Esther and Daniel.
* Different Order: While the content is similar, the order of the books differs between the Tanakh and the Catholic Old Testament.
* Greek Translation: The Catholic Church traditionally used the Greek translation of the Old Testament called the Septuagint (LXX) for its Old Testament. The Septuagint included the deuterocanonical books. The Septuagint contains some differences in the ordering of books and, in some cases, different versions of the original text.
In summary, the Catholic Old Testament is heavily based on the Tanakh, but it includes additional books, a different order, and is often based on the Greek Septuagint translation.