The Imitation of Christ (Thomas a Kempis) – pdf, epub, kindle; or audiobook here and here; or pdf here and here
Uniformity with God’s Will (St. Alphonsus de Liguori) – pdf, text, audio; pdf also here; or read online here; or audiobook here: part 1, part 2, or here
Humility of Heart (Fr. Gaetano M. da Bergamo) – pdf, kindle; or also here; or audio here; or read online here
The Way of Salvation and of Perfection (St. Alphonsus de Liguori) – pdf; also here
Abandonment to Divine Providence (Jean-Pierre de Caussade) – pdf, text, audio; or audiobook here; or pdf here
Trustful Surrender to Divine Providence (St. Claude de la Colombiere) – pdf; or pdf, epub, kindle format here
The Holy Will of God: A Short Rule of Perfection (Fr. B. Canfield) – pdf, text, kindle format
Letter to the Friends of the Cross (St. Louis Marie de Montfort) – pdf; or read online here; or audiobook here: part 1, part 2
The Spiritual Combat (Fr. Lorenzo Scupoli) – pdf; or pdf here or here; or audiobook here (12 parts) or here + (supplement)
The Practice of the Love of Jesus Christ (St. Alphonsus de Liguori) – pdf; or pdf, text, kindle format here and here
The Great Means of Salvation and Perfection (St. Alphonsus) – audiobook; or here: part 1, part 2
Preparation for Death (St. Alphonsus de Liguori) – pdf; or also here; or audiobook here (various parts) or here
The Art of Dying Well (St. Robert Bellarmine) – pdf, text, kindle; also pdf here; or audiobook here
An Easy Way to Become a Saint (Fr. P. O’Sullivan) – audiobook (4 parts); or also here; or pdf here
The Book of Confidence (Fr. Thomas de Saint Laurent) – pdf
The Practice of Perfection and Christian Virtues (Fr. Alphonsus Rodriguez) – pdf, text, kindle format (both volumes); or doc format: Vol I; Vol II
Introduction to the Devout Life (St. Francis of Sales) – pdf; or pdf here; or audiobook here, here or here
The Treatise on the Love of God (St. Francis de Sales) – pdf, kindle; or pdf here and here; or audiobook here
The Secret of Sanctity (St. Francis de Sales, Fr. J. Crasset) – pdf, text, epub, kindle format
The Ladder of Divine Ascent (St. John Climacus) – pdf; or audiobook – part 1, part 2
Little Book of Eternal Wisdom (Bl. Henry Suso) – pdf, text; or audiobook here (in 6 parts)
Calamities, Chastisement and the Love of God (St. Alphonsus de Liguori) – pdf, text, kindle; or pdf here
Practice of the Presence of God: The Best Rule for Holy Life (Brother Lawrence) – pdf, text, audio; audio here; or pdf here
On Loving God (St. Bernard of Clairvaux) – pdf, text, audio; or audiobook here; or pdf here; or read online here
Holiness of Life (St. Bonaventure) – pdf; or audiobook here and here
The Holy Ways of the Cross (Henri-Marie Bouden) – pdf; or pdf, text, kindle format here
The Interior Life (Fr. J. Tissot, St. Francis de Sales) – pdf, text, kindle format
The Quiet of the Soul (Fr. J. de Bovilla) + Cure for Scruples (Dom Schram) – pdf, text, kindle format
The Spiritual Exercises of St. Ignatius of Loyola (St. Ignatius) – pdf, text, audio; or audio here; or pdf here or here
The Spiritual Exercises of St. Ignatius Explained by Fr. M. Meschler – pdf, txt, epub, kindle format
The End of This Present World and the Mysteries of the Life to Come (Fr. Charles Arminjon) – pdf; or here
A Sinner’s Guide (Ven. Luis de Granada) – pdf; or pdf, text, epub, kindle format here
A Memorial of Christian Life (Ven. Luis de Granada) – pdf, text, epub, kindle format
Counsels on Holiness of Life (Ven. Luis de Granada) – pdf, text, epub, kindle format
All for Jesus: The Easy Ways of Divine Love (Fr. F. G. Faber) – pdf, text, epub, kindle format
Growth in Holiness, Or The Progress of the Spiritual Life (Fr. F. G. Faber) – pdf, text, kindle format
On Union with God (St. Albert the Great) – pdf, text, kindle format; or pdf here; or audiobook here
The Contrite and the Humble Heart (Fr. S. Jenks) – pdf, text, epub, kindle format
Christian Directory: Guiding Men to Their Eternal Salvation (Fr. R. Parsons) – pdf; or pdf, text, kindle here
Jesus Appeals to the World (Fr. L. Sales, Sr. Consolata Betrone) – pdf
The Littlest Way of Love: Message from the Heart of Jesus to Sr. Consolata Betrone (Fr. L. Sales) – pdf
The Way of Divine Love, or, The Message of the Sacred Heart to the World (Sr. Josefa Menendez) – pdf; or pdf, epub, kindle format here; or read online here; or audiobook here: part 1, part 2
As I Have Loved You (Fr. J. Kearney) – audiobook (12 parts)
The Difference Between Temporal and Eternal (Fr. E. Nieremberg) – pdf
My Daily Bread: Meditations (Fr. A. Paone) – pdf, text, kindle format; or audiobook here (various parts) or here
Prayer: The Great Means of Salvation and of Perfection (St. Alphonsus) – read online; or audiobook (various parts – all links here)
Prayer, the Key of Salvation (Fr. M. Mueller) – pdf, text, kindle format; or audiobook here (various parts)
How to Be Happy, How to Be Holy (Fr. P. O’Sullivan) – audiobook (8 parts); or also here [on prayer]
Prayer: Its Necessity, Its Power, Its Conditions (Fr. F. Girardey) – audiobook
Prayer, the Great Means of Grace – audiobook: part 1, part 2; or also here
The Ways of Mental Prayer (Dom V. Lehodey) – pdf, text, kindle format; or audiobook here; or pdf here
An Easy Method of Meditation (Fr. F. X. Schouppe) – pdf; or also here
A Golden Treatise of Mental Prayer (St. Peter of Alcantara) – pdf, text, kindle format
Of Prayer and Meditation (Ven. Luis de Granada) – pdf, text, epub, kindle format
Holy Wisdom: Directions for the Prayer of Contemplation (Fr. Augustine Baker) – pdf; or read online here
Progress Through Mental Prayer (Fr. E. Leen) – read online
The Practice of Mental Prayer (Fr. R. de Maumigny) – pdf, text, kindle format
Guide of the Man of Good Will in the Exercise of Mental Prayer (Fr. J. Simler) – pdf, text, kindle format
Time for God (Fr. J. Philippe) – pdf, epub, kindle format
The Three Ages of the Interior Life (Fr. Garrigou-Lagrange) – pdf; or epub here; or audio here (7 parts)
The Three Conversions in the Spiritual Life (Fr. R. Garrigou-Lagrange) – epub; or pdf here
Christian Perfection and Contemplation (Fr. R. Garrigou-Lagrange) – pdf; or pdf, epub here
The Love of God and the Cross of Jesus (Fr. R. Garrigou-Lagrange) – pdf: volume I, volume II
The Theology of Christian Perfection (Fr. A. Royo Marin) – pdf; or pdf, kindle here; or audiobook here
Spiritual Maxims (J. N. Grou) – pdf
The Paths of Goodness: Some Helpful Thoughts on Spiritual Progress (Fr. E. F. Garesche) – pdf
Solid Virtue: On the Obstacles to Solid Virtue, the Means of Acquiring, and Motives for Practicing It (Fr. Bellecius) – pdf
The Following of Christ (Fr. J. Tauler) – pdf, text, kindle format; or read online and pdf here
The Friendship of Christ (Mons. R. H. Benson) – audiobook; or pdf, kindle here; or read online here
Sufferings Sanctified – audiobook: part 1, part 2; or also here
Words of Consolation for the Sick and Afflicted (1959) – pdf; or audiobook here
The Ideal of Reparations (Fr. R. Plus) – pdf, text, epub, kindle format
The Agonizing Heart – Salvation of the Dying, Consolation of the Afflicted (Fr. F. R. Blot) – pdf, text, kindle: volume I, volume II
The Cloud of Unknowing (Anonymous, 14th cent.) – audiobook; or also here; or pdf here
The Spiritual Ascent: A Devotional Treatise (Gerard Zerbolt of Zutphen) – pdf, text, kindle format
The Wisdom of the Desert (James O. Hannay) – pdf, kindle format; or read online here
Half-Hours with the Saints and Servants of God (classified and divided by topic) – pdf, text, kindle format
Light and Peace: Instructions for Devout Souls to Dispel Their Doubts and Allay Their Fears (Fr. C. G. Quadrupani) – audiobook; or read online and pdf here
The Spiritual Man, or, The Spiritual Life Reduced to Its First Principles (Fr. J. B. Saint-Jure) – pdf
Christian Perfection (Abp. F. Fenelon) – pdf
Spiritual Progress (Abp. F. Fenelon) – audiobook (in 4 parts); or pdf, text here
Directorium Asceticum: Guide to the Spiritual Life (Fr. G. B. Scaramelli) – vol. I, vol. II, vol. III, vol. IV
Manual of Christian Perfection (Fr. G. B. Scaramelli; P. J. Stockman) – pdf, text, kindle format
Manual of Self-Knowledge and Christian Perfection (Fr. J. H. Schagemann) – pdf, text, kindle format
Three Fundamental Principles of the Spiritual Life (Fr. M. Mechler) – pdf, text, kindle format
The Foundations of the Spiritual Life (Fr. J. J. Surin) – pdf, text, kindle format
The Spiritual Doctrine of Father Louis Lallemant (Fr. L. Lallemant, Fr. F. W. Faber) – pdf, kindle; or here
Spiritual Theology (Fr. Jordan Aumann) – pdf, epub, kindle; or pdf here; or audiobook here
The Spiritual Life: A Treatise on Ascetical and Mystical Theology (Fr. A. Tanqueray) – pdf, kindle; or here
The Mystical Evolution (Fr. J. G. Arintero) – pdf: volume I, volume II
A Manual of Mystical Theology (Fr. A. Devine) – pdf, text, kindle format
Remember, or, Thoughts on: The End of Man, The Four Last Things, The Passion of Our Lord, Human Suffering, Humility and Patience (Fr. F. X. Lasance) – pdf
My Spiritual Exercises (Fr. J. Kearney) – audiobook (various parts)
Meditations on the Love of God (Fr. Diego de Estella) – pdf, text, kindle format
Meditations on the Mysteries of Our Holy Faith (Fr. Luis de la Puente) – vol. I, vol. II, vol. III, vol. IV, vol. V, vol. VI
Think Well on’t: Reflections on the Great Truths of the Christian Religion for Every Day in the Month (Bp. R. Challoner) – pdf, epub, kindle format
Perfect Contrition: The Golden Key to Paradise (Fr. J. de Driesch) – pdf, or also here; or audiobook here: part 1, part 2, or here
Perfect Contrition (Fr. F. Quirijnen) – pdf; or also here
Heaven Open to Souls: Love for God Above All Things and Perfect Contrition (Fr. H. C. Semple) – pdf; or here
The Conquest of Heaven: Perfect Charity and Contrition (Fr. F. Rouvier) – pdf
Attention Catholics! (Helpful Reminders for Catholics Living in the Modern Confusion) – pdf
The Catholic Educator: A Library of Catholic Instruction and Devotion, Masterpieces of Great Spiritual Masters, with Illustrated Explanation of the Doctrines, Liturgy, Rites and Ceremonies of the Church – pdf, text, kindle