- ✠ St. Cajetan of Thiena, Founder of the Regular Clerics, known as Theatines
- ✠ St. Callistus I, Pope and Martyr
- ✠ St. Camillus of Lellis, Founder of the Servants of the Sick
- ✠ Saint Canutus, King of Denmark, Martyr
- ✠ Saint Casimir, King of Poland
- ✠ St. Catherine Labouré, Virgin, Visionary
- ✠ St. Catherine of Alexandria, Virgin, Martyr, Patroness of Students and Young Girls
- ✠ St. Catherine of Genoa, Widow
- ✠ St. Catherine of Ricci, Virgin
- ✠ St. Catherine of Siena, Virgin, Dominican Nun
- ✠ Bl. Catherine of St. Augustine, Virgin
- ✠ St. Catherine of Sweden, Queen and widow, daughter of Saint Bridget
- ✠ Saint Cecilia, Virgin, Martyr
- ✠ St. Celestine I, Pope
- ✠ St. Charbel Makhlouf, Maronite Priest and Hermit
- ✠ St. Charles Borromeo, Archbishop of Milan
- ✠ Saint Christina, Virgin and Martyr
- ✠ Saint Christopher, Martyr
- ✠ Sts. Chrysanthus and Daria, Martyrs
- ✠ Circumcision of Our Lord
- ✠ St. Clare of Assisi, Foundress and Abbess
- ✠ St. Clare of Montefalco, Virgin
- ✠ Saint Claude, Archbishop
- ✠ St. Clement I of Rome, Pope and Martyr
- ✠ St. Clement Mary Hofbauer, Redemptorist Priest, confessor
- ✠ Sts. Cletus and Marcellinus, Popes and Martyrs
- ✠ Saint Clodoald, (or Cloud), Confessor
- ✠ Saint Clotilda, Queen of France
- ✠ Saint Colette, Virgin, Reformer of the Poor Clares
- ✠ St. Columban, (or Columbanus), Abbot
- ✠ St. Columkille, (or Columba), Abbot
- ✠ Commemoration of St. Paul, Apostle of the Gentiles
- ✠ St. Conrad of Piacenza, Hermit
- ✠ Sts. Cosmas and Damian, Martyrs
- ✠ Sts. Crispin and Crispinian, Martyrs
- ✠ Exaltation of the Holy Cross
- ✠ Finding of the Holy Cross
- ✠ St. Cunegundes, Empress
- ✠ Saint Cyprian, Doctor of the Church, Bishop of Carthage and Martyr
- ✠ Sts. Cyprian and Justina, Martyrs
- ✠ Sts. Cyriacus and Companions, Martyrs
- ✠ Sts. Cyril and Methodius, Apostles to the Slavic Nations
- ✠ St. Cyril of Alexandria, Doctor of the Church
- ✠ St. Cyril of Jerusalem, Bishop, Confessor, Doctor
- ✠ St. Cyril, child martyr
