Bibliotheca Catholica
Reference Works
Encyclopedias, dictionaries, the Summa, patristic collections, liturgy, chant, saints, and apologetics.
- Catholic Encyclopedia (1913) — New Advent — The classic 15-volume Catholic Encyclopedia, fully online.
- Wikisource: Portal Catholicism — Wikisource's hub for Catholic texts: papal documents, creeds, councils, and the Fathers.
- Catholic Encyclopedia (1913) — Wikisource — Proofread transcription with page scans.
- Catholic Answers Encyclopedia — Catholic Answers' online encyclopedia.
- Modern Catholic Dictionary (Fr. John Hardon) — Over 5,000 Catholic terms defined.
- Logeion (Latin & Greek) — Lewis & Short, LSJ, and more in one search.
- Whitaker's Words (Latin parser) — Latin–English parser and dictionary (Notre Dame).
- Lewis & Short on Perseus — Perseus Digital Library: Latin/Greek texts and lexica.
- Summa Theologiae — New Advent — Complete Summa (Benziger 1920 translation).
- Aquinas Institute — Latin/English Opera Omnia — Parallel Latin–English works of St. Thomas.
- Corpus Thomisticum — Complete Latin works of St. Thomas with Index Thomisticus.
- St. Thomas Aquinas's Works in English (isidore.co) — Fr. Joseph Kenny's compilation of Aquinas in English, hosted by isidore.co.
- Fundamentals of Catholic Dogma (Ott) — isidore.co — Ludwig Ott's classic manual of dogma.
- Fathers of the Church — New Advent — Ante-Nicene and Nicene/Post-Nicene Fathers in English.
- Early Church Fathers — CCEL (ANF/NPNF) — Schaff's 38-volume Ante-Nicene, Nicene and Post-Nicene Fathers.
- Tertullian Project & Additional Fathers — Roger Pearse's collection of patristic texts not in Schaff.
- Patrologia Latina & Graeca (Documenta Catholica Omnia) — Migne's Patrologia and thousands of Latin/Greek texts.
- Augustinus.it — Opera Omnia of St. Augustine — Complete Latin works of Augustine with Italian (and some English) translations. If the site is down, use the Internet Archive copy: the snapshot of 5 October 2026.
- Corpus Corporum (Latin texts) — University of Zurich repository of Latin texts, including Migne.
- Sources Chrétiennes — Critical editions of patristic texts (Lyon).
- Divine Office (Liturgy of the Hours) — The Liturgy of the Hours online, with audio.
- Liturgical Year — Catholic Culture — Each day of the Church year: feasts, Mass propers, prayers, family activities, and recipes, from CatholicCulture.org.
- iBreviary — Breviary, missal, and prayers in many languages.
- Divinum Officium (traditional breviary & missal) — Traditional Roman Breviary and Missal by date (1570–1962 rubrics).
- General Instruction of the Roman Missal (USCCB) — Norms for celebrating the Mass.
- Roman Martyrology (Internet Archive) — The Church's official list of saints (scans of English editions).
- GregoBase — Gregorian chant database — Thousands of Gregorian chants in GABC/PDF.
- Church Music Association of America — chant books — Free PDFs of the Graduale Romanum, Liber Usualis, and more.
- Choral Public Domain Library — Free sacred choral scores — Palestrina, Victoria, Byrd, and more.
- Butler's Lives of the Saints (CCEL) — Alban Butler's Lives of the Saints.
- The Golden Legend (Fordham Medieval Sourcebook) — Jacobus de Voragine's medieval collection of saints' lives.
- Catholic Saints — Franciscan Media Saint of the Day — Daily saint biography and reflection.
- Catholic-Hierarchy.org — Every bishop and diocese, past and present.
- GCatholic.org — Dioceses, churches, cardinals, and religious orders worldwide.
- Catholic Answers — The largest English-language apologetics apostolate: tracts, Q&A, magazine.
- Scripture Catholic — Bible verses and Fathers organized by Catholic doctrine.
- Called to Communion — Reformed-to-Catholic converts' essays and dialogue.
- Coming Home Network — Support for clergy and laity journeying into the Church.
- Encyclopedia of Catholic Theology (ECT) — Peer-reviewed scholarly entries on dogmatic, moral, and philosophical theology, with a lexicon and short Q&A responses.
- Catholic Answers Q&A — Thousands of short answers to common questions about the Faith.
- Web Gallery of Art — Searchable database of European painting and sculpture, rich in sacred art from the Middle Ages to the 1900s.
- Catholic Resources: Biblical and religious art (Felix Just, S.J.) — Fr. Felix Just's guide to biblical art, iconography, and music online.