The only saint to be canonized in the Roman Catholic Church based solely on the results of her powerful intercession, St. Philomena is known as a great intercessor of many favors, graces and miracles.

Little is known of St. Philomena's life, except that she was martyred around the age of thirteen. Her tomb was discovered on May 25, 1802 in the ancient Catacomb of St. Priscilla in Rome. Her tomb was sealed with terra cotta slabs with an inscription that read, Pax tecum, Filumena, which means "Peace be with you Philomena." On the slabs were also inscribed several symbols: a lily, arrows, an anchor and a lance, which are considered by many to be symbols of virginity and martyrdom. A vial of her dried blood, also often considered to be a common item included with the burial of Christian martyrs of the early church, was also in the tomb. Together, these symbols and signs are the only tangible evidence of her virginity and martyrdom at such a young age.

Upon the discovery of her tomb, Philomena's remains were transported to the Treasure of the Rare Collections of Christian Antiquity in Rome and soon forgotten. It was not until 1805 that Neapolitan priest Don Francesco di Lucia requested to receive the relics of the martyr to enshrine in his village church at Mugnano, near Naples.

When Philomena's remains were donated to Mugnano, unusual events began to occur and many favors were secured through her intercession. The favors, graces and miracles began to increase, so much that she became known as "Philomena, Powerful with God." In 1835, Pauline Jaricot was miraculously healed of a life-threatening illness when she traveled to the shrine at Mugnano and was placed before Philomena's relics. Pope Gregory XVI witnessed the result of the healing, and immediately opened the investigation into her sainthood. Gregory XVI canonized her in 1837 and named her the Patroness of the Living Rosary and the Patroness of the Children of Mary.

Saint Philomena has become a patron of hopeless cases, and her help is particularly sought in cases of conversion of sinners, return to the Sacraments, mothers, children, pregnancy, help for the sick, help for the missions, money problems, food for the poor and mental illness.