The diocese of Quilon is consecrated to the special protection and intercession of the Blessed Mother Mary of Mount Carmel. The providential care of God revealed to the Israelites through the intercession and defense of their faith by the great Prophet Elijah on Mount Carmel and that has been newly and experientially concretized in the Salvation history of the New Covenant through the motherly providence and defending to the faith of the church, consecrated to Mary's care. The diocese is protected and guided by the Spirit of purity and continued intercession of the Blessed Mother Mount Carmel.

On April 24, 1838 the Holy See established the Vicariate of Malabar with headquarters at Verapoly and Quilon became part of the new vicariate. The separation of Quilon, as a new Vicariate Apostolic, suffragan to Verapoly was decreed and was provisionally executed on May 12, 1845, entrusting it to the Belgian Carmelite Missionaries , and finally confirmed as a separate Vicariate Apostolic on March 15, 1853. Since diocese has been served by the Carmelite Missionaries, they have dedicated their ministries and the diocese to the Mother Mary of Mount Carmel. Thus ever since they under took the diocese, Mount Carmel has been considered and honoured to be the Patroness of the diocese.

Carmelites see in the Virgin Mary, Mother of God and archetype of the Church, the perfect image of all that they want and hope to be. For this reason, Carmelites have always thought of Mary as the Patron of the Order, its Mother and Splendour; she is constantly before their eyes and in their hearts as the Virgin Most Pure. Looking to her, and living in spiritual intimacy with her, they learn to stand before God, and with one another, as the Lord's brothers. Mary lives among them, as mother and sister, attentive to their needs; along with them she waits and hopes, suffers and rejoices. The scapular is a sign of Mary's permanent and constant motherly love for Carmelite brothers and sisters. By their devotion to the scapular, faithful to a tradition in the Order, especially since the 16th century, Carmelites express the loving closeness of Mary to the people of God; it is a sign of consecration to Mary, a means of uniting the faithful to the Order, and an effective and popular means of evangelization.