- ✠ Saints Abdon and Sennen, Persian Martyrs at Rome
- ✠ Sts. Abraham and Mary, Solitary and Priest, and his niece
- ✠ Sts. Adrian and Eubulus, Martyrs
- ✠ Saint Agapetus, Martyr
- ✠ Saint Agatha, Virgin and Martyr
- ✠ Saint Agnes, Virgin and Martyr
- ✠ St. Agnes of Monte Pulciano, Virgin, Augustine Nun
- ✠ Saint Albert the Great, Dominican Priest, Doctor of the Church
- ✠ Saint Albinus, Bishop
- ✠ St. Alexander I and Companions, Pope
- ✠ Saint Alexius of Rome, Confessor
- ✠ Saint Alfred, (or Aelred), Abbot
- ✠ All Saints Day
- ✠ All Souls Day, Commemoration of the Faithful Departed
- ✠ Saint Aloysius Gonzaga, Jesuit Seminarian
- ✠ St. Alphonsus Liguori, Bishop and Doctor of the Church, Founder of the Redemptorists
- ✠ Saint Alphonsus Rodriguez, Confessor, Jesuit Coadjutor
- ✠ Saint Ambrose, Bishop of Milan and Doctor of the Church
- ✠ Bl. Ambrose Leblanc, Franciscan Provincial
- ✠ Saint Anacletus, Pope and Martyr
- ✠ Saint Andrew, Apostle and Martyr
- ✠ Saint Andrew (with Peter, Paul and Dionysia), Martyr
- ✠ Saint Andrew Avellino, Theatine Priest
- ✠ Saint Andrew Bobola, Jesuit, Martyr
- ✠ St. Andrew Corsini, Bishop of Fiesole
- ✠ Saint Andrew Kim, the first Korean Priest, Martyr
- ✠ Saint Angela Merici, Virgin, Foundress of the Ursulines
- ✠ St. Angela of Foligno, Widow
- ✠ Guardian Angels
- ✠ St. Anicetus, Pope, Martyr
- ✠ Bl. Anna Maria Taigi, Wife and mother, Trinitarian Tertiary
- ✠ Saint Anne, Mother of the Blessed Virgin
- ✠ Annunciation, of the Blessed Virgin Mary and the Incarnation of the Word of God
- ✠ Saint Anselm, Archbishop of Canterbury
- ✠ St. Anthony Maria Zaccaria, Founder of the Order of Regular Clerics of Saint Paul, since called Barnabites
- ✠ St. Anthony Mary Claret, Founder of the Claretian Fathers and the Sisters of Mary Immaculate
- ✠ Saint Anthony of Padua, Doctor of the Church and Miracle-Worker
- ✠ St. Anthony of the Desert, Patriarch of Monastic Life
- ✠ Saint Antoine Daniel, North American Martyr
- ✠ Saint Antoninus, Archbishop of Florence
- ✠ Saint Apollinaris, First Bishop of Ravenna and Martyr
- ✠ St. Apollinaris the Apologist, Bishop
- ✠ Saint Apollonia, Virgin, and companions, Martyrs of Alexandria
- ✠ St. Apollonius, Martyr
- ✠ Saint Arcadius, Martyr
- ✠ Assumption, of the Blessed Virgin Mary
- ✠ Novena - Assumption
- ✠ St. Athanasius, Bishop, Doctor of the Church
- ✠ Saint Attalus, Martyr
- ✠ Saint Augustine, Bishop of Hippo and Doctor of the Church
- ✠ St. Augustine of Canterbury, Apostle of England
- ✠ Saint Avitus, Abbot
