One of the distinguishing features of Catholic Bibles is that they contain the deuterocanonical Old Testament books of Tobit, Judith, 1 and 2 Maccabees, Wisdom of Solomon, Ecclesiasticus (or, Sirach), and Baruch, intermingled with the other books of the Old Testament. So, look in the Table of Contents for these books. If they are included but grouped together in a section by themselves entitled Apocrapha, then its not a Catholic Bible.
As far as I know, Catholic Bibles also contain, near the title page, a Catholic censor’s Nihil Obstat (Latin: nothing obstructs) and a Catholic bishop’s Impimatur (Latin: let it be printed) followed by their names.
Some approved versions of the Catholic Bible in English are:
The Douay-Rheims Bible
The Jerusalem Bible
The New Jerusalem Bible
The New American Bible
The Revised Standard Version - Catholic Edition
The New Revised Standard Version - Catholic Edition