Cardinals of the Holy Roman Church – Biographical entries of the 16th to the 21st century cardinals and of the events and documents concerning the origin of the Roman cardinalate and its historical evolution
Catechism of the Catholic Church (2nd ed., 1997) – The Second Edition English Translation of the Catechism of the Catholic Church includes the corrections promulgated by Pope John Paul II on 8 September 1997.
Catholic Encyclopedia (1913) – Full-text (Pre-Vatican II) edition.
Catholic Resources for Bible, Liturgy, Art and Theology – A resource project of Fr. Felix Just, S.J., PhD
Code of Canon Law – Includes searchable text, glossary, concordance as well as statistics and graphs.
Code of Canons of Oriental Churches – Canons that solely affect the Eastern Catholic Churches (unless expressly stated otherwise).
Hierarchy of the Catholic Church – Includes information on apostolic nuncios (past and present), titular sees, bishops, geographical and historical information.
International Marian Research Institute, University of Dayton – Access to one of the largest international centers of study, research and teaching on the Mother of Jesus.
Marian Apparitions Pages – Hosted by the University of Dayton, includes statistical data, FAQs, bibliographies and ecclesiastical information.
Papal Encyclicals Online – Guide to online papal and official documents of the Catholic Church (not Vatican-affiliated).
Patron Saints Index – Information on topics with patron saints, and profiles of those saints. Profiles have portraits, biographical information, areas of patronage, prayers, links to related sites, readings, etc.
U.S. Catholic Bishops – Contact information by diocese and state.