http://www.ccel.org/ccel/schaff/encyc01.a.html
- Justin Edwards Abbott
- Lyman Abbott
- Thomas Kingsmill Abbott
- David Abeel
- Louis Abelli
- Aben Ezra
- John Abercrombie
- John Abernethy
- Friedrich Philip Von Abert
- Swami Abhedananda
- Isaac Abravaneel Abravaneel, Abarbanul
- Abraham A Sancta Clara
- Abraham Ecchellensis
- Israel Abrahams
- Laurentius Abrahamson
- Absalon (Axel)
- Abulfaraj
- Acacius of Beroea
- Acacius of Caesarea
- Acacius of Constantinople
- Acacius of Melitene
- Acca
- Accolti
- Pietro Accolti
- Benedetto Accolti
- Ernst Christian Achelis
- Hans Achelis
- Jean Luc Achery
- Johann Heinrich Achterfeldt
- Jose de Acosta
- Uriel Acosta
- John Emerich Edward Dalberg Acton
- Adalbert (Adelbert, Aldebert)
- Adalbert of Hamburg-Bremen
- Adalbert of Prague
- Adalbold
- Adaldag
- Adalgar
- Adalhard and Wala
- Adam of Bremen
- Adam, Melchior
- Adam of Saint Victor
- Adam the Scotchman
- Adamnan
- Adams George Moulton
- Adams James Alonzo
- Adams John Coleman
- Adams, Sarah Flower
- Adams, Thomas
- Adams, William
- Adams, William Forbes
- Adamson, Patrick
- Adamson, William
- Addicks, George B.
- Addis, William Edward
- Addison, Daniel Dulany
- Adelmann
- Adeney, Walter Frederic
- Adler, Cyrus
- Adler, Felix
- Adler, Hermann Nathan
- Adler, Nathan Marcus
- Ado
- Adrian
- Adso
- Aegidius de Columna
- Aegidius of Viterbo
- Aeneas of Gaza
- Aeneas of Paris
- Aepinus, Johannes
- Aerius
- Affre, Denis Auguste
- Afra, Saint
- Agapios Monachos
- 3.
- Agatha, Saint
- Agelli, Antonio
- Agier, Pierre Jean
- Agilbert
- Agliardi, Antonio
- Agnellus
- Agnes, Saint
- Agobard
- Agricola
- Agricola, Johann
- Agricola, Stephan
- Agrippa Castor
- Agrippa von Nettesheim, Heinrich Cornelius
- Aguirre, Joseph Saenz de
- Ahaus, Heinrich von
- Ahlfeld, Johann Friedrich
- Aichspalt
- Aidan, Saint
- AIDAN, ai�dan, SAINT: First bishop of Lindisfarne; d. at
- Aiken, Charles Augustus
- Ailly, Pierre D
- Ailred
- Aimoin
- Aimoin of St. Germain:
- 2. Aimoin of Fleury:
- Ainger, Alfred
- Ainsworth, Henry
- Aitken, William Hay Macdowall Hunter
- Aked, Charles Frederic
- 1. Alanus of Auxerre:
- 2. Alanus: Abbot of Tewkesbury.
- 3. Alanus ab Insulis (Alain of Lille); o
- Alban, Saint, of Mainz
- Alban, Saint, of Verulam
- Alber, Erasmus
- Alber, Matthaeus
- Albert of Aix
- Albert
- Albert V. of Bavaria and the Counter Reformation In Bavaria
- Albert of Brandenburg
- Albert the Great
- Albert of Prussia
- Albert of Riga
- Alberti, Valentin
- Albertini, Johann Baptist von
- Albertus, Magnus
- Albizzi, Antonio
- Albizzi, Bartolomeo
- Albo, Joseph
- Albrecht
- Albrecht, Otto Wilhelm Ferdinand
- Albright, Jacob
- Alcimus
- Alcuin
- Aldebert
- Aldhelm Saint
- Aleandro, Girolamo
- Alegambe, Philippe D’
- Alesius, Alexander
- Alexander
- Alexander, Patriarch of Alexandria
- Alexander Balas
- Alexander of Hales
- Alexander of Hierapolis
- Alexander Jannæus
- Alexander of Lycopolis
- Alexander Nevsk
- Alexander Severus
- Alexander, Archibald
- Alexander, Charles McCallon
- Alexander, George
- Alexander, Gross
- Alexander, James Waddell
- Alexander, Joseph Addison
- Alexander, William
- Alexander, William Lindsay
- Alexius I., Comnenus
- Alford, Henry
- Alfred the Great
- Alfric
- Alger, of Liege
- Alger, William Rounseville
- Allard, Paul
- Allatius, Leo
- Allegri, Gregorio
- Alleine, Joseph
- Alleine, Richard
- Allemand, Louis D.
- Allen, Alexander Viets Griswold
- Allen, Henry
- Allen, John
- Allen, Joseph Henry
- Allen, William
- Alley, William
- Allies, Thomas William
- Allioli, Josef Franz
- Allix, Pierre
- Allon, Henry
- Almain, Jacques
- Almeida, Manoel
- Alogi
- Aloysius, Saint, of Gonzaga
- Alphæus
- Alsted, Johann Heinrich
- Altenstein, Karl Freiherr von Stein Zum
- Althamer, Andreas
- Althaus, Paul
- Alting, Johann Heinrich
- Altmann
- Altmann, Wilhelm
- Alvar of Cordova
- Alypius, Saint
- Alzog, Johann Baptist
- Amalarius of Metz
- Amalarius of Treves
- Amalric of Bena
- Amandus
- Amandus, Johannes
- Ambo
- Ambrose of Alexandria
- Ambrose the Camaldolite
- Ambrose Saint, of Milan
- Ambrose, Isaac
- Ames, William
- Amice
- Amiot, Joseph Maria
- Amling, Wolfgang
- Ammianus Marcellinus
- Ammon, Christoph Friedrich von
- Ammonius
- Ammonius the Hermit
- Ammonius Saccas
- Amolo
- Amphilochius, Saint
- Amraphel
- Amsdorf, Nikolaus von
- Amyot
- Amyraut, Moise
- Anastasius
- Anastasius
- Anastasius Bibliothecarius
- Anatolius of Constantinople
- Anatolius of Laodicea
- Anchieta, Jose de
- Anderson, Charles Palmerston
- Anderson, Galusha
- Anderson, Joseph
- Anderson, Lars
- Anderson, Martin Brewer
- Anderson, Rufus
- Anderson, William Franklin
- Andrada, Antonio D.
- Andrada, Didacus,
- Andrea, Jakob
- Andrea, Johann Valentin
- Andrea, Lorenz
- Andrew the Apostle
- Andrew of Cæsarea
- Andrew of Carniola
- Andrew of Crete
- Andrew of Lund
- Andrewes, Lancelot
- Andrews, Edward Gayer
- Andrews, Elisha Benjamin
- Andrews, Samuel James
- Andrews, William Watson
- Angela of Brescia
- Angelis, Girolamo
- Angilbert, Saint
- Angilram
- Anglus, Thomas
- Angus, Joseph
- Anicetus
- Anna
- Anna Comnena
- Annas
- Anne, Saint
- Annet, Peter
- Anno
- Anomoios
- Anrich, Gustav Adolf
- Ansegis
- Anselm, Saint, of Canterbury
- Anselm of Havelberg
- Anselm of Laon
- Anselm of Lucca
- Ansgar
- Anso
- Anterus
- Anthony, Alfred Williams
- Anthony, Saint, the Hermit
- Anthony, Saint, Orders of
- Anthony, Saint, of Padua
- Antiochus, Kings
- Antiochus, Abbot
- Antipas
- Antipater of Bostra
- Antiphon
- Anton, Paul
- Antonelli, Giacomo
- Antoninus Pius
- Antoninus, Saint, of Florence
- Antonio de Lebrija
- Aphraates
- Apion
- Apollinaris, Claudius
- Apollinaris of Laodicea
- Apollonia, Saint
- Apollonius
- Apollonius of Tyana
- Apollos
- Aportanus, Georg
- Appel, Theodore
- Appleton, Jesse
- Apponius
- Aquaviva, Claudio
- Aquila
- Aquila Kaspar
- Aquinas
- Arakin
- Arator
- Flavius Arcadius
- Archelaus
- Archiereus
- Giovanni Angelo Arcimboldi
- Aretas
- Arethas
- Benedictus Aretius
- Benedictus Arias
- Aribo (bishop)
- Marcianus Aristides
- Thomas Armitage (Baptist)
- Arnauld family
- Augustin Arndt
- Johann Friedrich Wilhelm Arndt
- Arno of Reichersberg
- Carl Franklin Arnold
- Nikolaus Arnold
- Rosamunde Juliane von Asseburg
- Johann Baptist Maria Assmann
- Jean Frédéric Astie
- James Atkins (Methodist)
- William Wallace Atterbury (Presbyterian)
- Edward Robert Atwill
- Isaac Morgan Atwood
- Leonhard Atzberger
- Edme Aubertin
- Sister Augustina
- Avercius of Hieropolis Avircius, Abercius
- Henry Damerel Aves
- Joseph Cullen Ayer, Jr.