On the 8th of July 1836, Pope Gregory XVI made Madurai an Apostolic Province. Pearl fishery coast which came this new province was entrusted to the Jesuit Missionaries of Thulus Province in France. Those days Our Lady of Snows church was taken care of by the priests of Mylapore diocese which belonged to the Portuguese Mission. Thus the Jesuit Missionaries felt that they need a separate church to function from.
Rev. Fr. Kasthanier, who was the Superior of the Jesuit region of Palayamkottai, which came the pearl fishery coast, wanted to build a new church at Thoothukkudi. He bought the Land where the present church stands, for a cheap price from Mr. Manuel Viyagula Motha and put up a thatched church.
In 1849 Rev. Fr. Kanos became the Superior of the Jesuit Region of Palayamkottai. He wanted to build a larger church at Thoothukkudi. Thus Rev. Fr. Cori who was ministering at Thoothukkudi laid the foundation stone for the new church. Rev. Fr. Cori was succeeded by Rev. Fr. Piccinelli, who continued the construction work.
Rev. Fr. Kanos, who by then had been consecrated as bishop of Madurai Apostolic Province (22nd May 1848), blessed the new church, built by the tireless effort of Fr. Piccinelli, on 5th January 1849. The new church was dedicated to the Sacred Hearts of Jesus and Mary. Pope Pius IX sent the relics of St. Fidelis as a gift to this new church. Bishop Kanos placed the relics of St. Fidelis in a separate altar, and declared St. Fidelis as the Patron of the town of Thoothukkudi.
Though the church had been blessed, the construction work still continued. Jesuit brother Lamoth who was an expert in construction laboured strenuously and completed the church in 1864. In 1909 Rev. Fr. Martin extended the side wings of the church.
In 1923 this massive beautiful church was elevated as the Cathedral of the diocese of Thoothukkudi. In 1948 Bishop Tirurtius Roche, erected the sky scraping towers. The Cathedral had gone renovations during the golden as well as the platinum jubilee of the diocese. The Eucharistic adoration chapel was blessed by Bishop Amalnather on 06th August 1997.