Saint Robert Bellarmine, S.J. (1542 - 1621) was an Italian Jesuit and a Cardinal of the Catholic Church. In 1930 he was canonized a saint and named Doctor of the Church. He is also considered one of the most important figures in the Counter-Reformation.

He was a professor of theology and he later became the rector of the Roman College. In 1602 he became Archbishop of Capua. Bellarmine was a supporter of the Council of Trent.

Independent of his political role in the Catholic church he St. Bellarmine was a brilliant writer, producing a number of important works including this commentary on the full Psalter. In it he gives a full and plain meaning of each psalm.

This commentary is cross-linked with the Douay-Rheims version of the Bible.