Also known as the Roman Catechism and the Catechism of Pius V, this authoritative Catechism of the Catholic faith was commissioned by the Council of Trent and compiled under the direction of St. Charles Borromeo. Published at the command of Pope Pius V in 1566, it remained the official manual of popular instruction for the Catholic Church for over 400 years, until the promulgation of the new Catechism of the Catholic Church.

This electronic edition, which presents the esteemed 1923 McHugh/Callan translation, has been proofread (correcting hundreds of typographical errors in other online versions) and is specially formatted for optimal display on the Kindle, a visible improvement upon other public domain versions.