Refugium Peccatorum, Refuge of Sinners, is a title of the Blessed Virgin Mary.
Fr. Reginald Garrigou-Lagrange, O. P. (b. 1877- d. 1964) writes of Mary under this title in his book, The Mother of the Savior. Here is an excerpt:
Mary is Refuge of sinners precisely because she is so holy. Detesting sin, which does so much harm to souls, she welcomes sinners and wishes to bring them to repentance. She frees them from the bonds of sinful habits by the power of her intercession; she obtains their reconciliation with God by the merits of her Son, and reminds the sinner too of the same merits. Once converted to penance, she protects them from Satan, against everything which could lead to fresh falls. She helps them to learn of the sweetness of penance.
To her, after Jesus, all sinners now in Heaven owe their salvation. she has converted them in countless numbers, especially in places of pilgrimage —- at Lourdes where she issued the invitation ‘Pray and do penance,’ and more recently at Fatima where the number of conversions since 1917 is known to God alone. There are many condemned criminals who owe to her their conversion at the last moment. She has inspired the foundation of religious orders consecrated to prayer, to penance, and to the apostolate of the conversion of sinners — those of St. Dominic and of St. Francis, the Redemptorists, the Passionists, and so many others.
What sinners are there whom she does not protect? Those only who despise God’s mercy and call down His malediction on themselves. She is not the refuge of those who are obstinate in evil —- in blasphemy, perjury, impurity, avarice, pride of the spirit. But even to them she sends from time to time, as Mother of Mercy, graces for the mind and the will, and if they accept them they will be led from grace to grace and finally to the grace of conversion. To such she has suggested by the lips of a dying mother that they should say at least one Hail Mary each day, and often it has happened that though they made no other effort than that to change their lives, the feeble spark of good-will it contained was enough to light them the way to a worthy and penitent reception of the Last Sacraments. They have been laborers of the last hour, called and saved by Mary.  For almost two thousand years Mary has been the Refuge of sinners.
If you find it difficult to pray, say one Hail Mary each day. The Hail Mary:
Hail Mary, Full of Grace. The Lord is with thee. Blessed art thou among women, and blessed is the fruit of thy womb, Jesus.
Holy Mary, Mother of God, pray for us sinners now, and at the hour of our death. Amen.
Have a beautiful day.
Pictured: Antonio Baldinucci (b. 1665-d. 1717), Italian Jesuit priest and preacher. “Baldinucci had a particular devotion to the Virgin Mary, and made sure that a copy of miraculous picture of her as the Refuge of Sinners from the Church of the Gesu (Frascati) was carried with him in his travels. He also worked diligently to spread Marian devotions in his travels.” (from Anthony Baldinucci)
“When in 1717 Father Baldinucci fell ill with his final illness, he asked to be placed in his room this image of Mary, before which he repeatedly prayed, ‘Show yourself to be a Mother.’ As his end neared, he gazed sometimes heavenward, sometimes toward the picture, uttering the aspiration, ‘Jesus and Mary, my hope.'” (from more on Blessed Anthony Baldinucci)
Fr. Baldinucci has been declared Venerable and beatified, but not yet canonized.