The suppression of the Desmond Rebellion in 1581 marked the end of the old Gaelic Rule in the south of Ireland. In 1584 Sir John Norreys, Lord President of Munster, established his headquarters at Mallow. St. Anne's, the old Parish Church of Mallow, now in a ruined state, then passed to the Reformed Church. Through the following centuries, the Roman Catholic population attended Mass in various humble locations around the town.

The best known of these was the thatched Mass-house on the side street known as Chapel Lane. When this Mass-house was demolished in 1940-41 a small silver Chalice and accompanying Paten were found concealed in a wall cavity. The Chalice is of Spanish design and craftsmanship. It bears the date 1680 and the inscription "Ora Pro P.N.M.". There is an altar stone inset in its base. The Chalice and Paten are still used on special occasions in St. Mary's Church.

Over the years friendly relationships developed between the people of the town and the proprietors of Mallow Castle. Charles Denham Jephson-Norreys donated a site south of Main St. for the construction of a Roman Catholic Church. Here in 1818 the Church of St. Mary was built. This was a triumph for ecumenism in an intolerant age when the struggle for emancipation was still eleven years from victory. Fr. Thomas Barry, the Parish Priest of the time, led his congregation from their old Mass-house in Chapel Lane to, what must have seemed to them then, an imposing structure.

William O'Brien, M.P., a Mallow politician of strong Nationalist views, was not impressed. "It is", he said, "as barn-like as humility could make it, in order to soften the wrath of the Ascendancy". At that early stage it had an earthen floor and lacked seats.

St. Mary's Church was originally built behind a row of houses that stood along Main St. Access was by a narrow lane to the west and south of the present Credit Union building, formerly the National Bank. It was unacceptable in the days before Catholic Emancipation in 1829 to have a Catholic Chapel in a prominent position. These houses were gradually removed, thus providing a piazza fronting on to Bank Place. A row of horse chestnut trees, which grew in front of the Church, was removed in the 1940s. The Rev. Archdeacon Corbett put up the Calvary and the inscription on the wall behind it.

In 1900 Canon John Wigmore, the Parish Priest, built the present Romanesque facade and laid the foundations for the campanile, which was completed some five years later. The money to complete the campanile and clock of St. Mary's was bequeathed by Mr. Francis Fitzpatrick, landlord of the Hibernian Hotel at that time.

On an interesting footnote on ecumenical relations in Mallow at the time, an exchange of bells was made between the Church of St. Mary and the Church of St. Anne. Before the front of St. Mary's was erected in 1900, the Church bell was mounted on timbers at the back of the Church. The present bell in St. Mary's was originally mounted in St. Anne's, Church of Ireland. When the campanile was first erected, the old bell suspended on irons was affected by resonance from the limestone structure. The bell at St. Anne's Church was found to be suitable for the campanile so an exchange of bells took place. The old bell from St. Mary's was transferred to St. Anne's belfry where it worked perfectly and is still rung to this day.

For the 1900 improvements, Canon Wigmore employed an Italian family named 'Orangie' to do the plaster work. They produced some lovely tracery works on the ceilings.

With the advent of Vatican Two, many changes were made to the interior of the Church. The two side galleries, the altar rails and the pulpit were removed. In keeping with Vatican Two, a new altar was put in place whereby the priest would now face the congregation while celebrating Mass.

Over the years St. Mary's has grown on the loyalties and affections of the Mallow people. It has extended a welcome to them in times of joy in Christenings and Weddings. It has harboured their grief at times of sorrow in tragedies and obsequies. It links, as no other place does, the living with the dead generations in the cemetery behind the Church.

In 1968, when the church of St. Mary was 150 years old, a professional survey of the main roof found serious cause for concern. Remedial work was then undertaken. It was not possible to carry out the radical reconstruction, as recommended by the specialists, because of the commitment to complete the Church of the Resurrection. Over the past 25 years the situation has been monitored and repairs were done, as occasion demanded, generally in the wake of storm damage. A sheaf of reports in 1992 and 1994 indicated that major works involving the replacement of the 200-year-old roof and ceiling should be undertaken as a matter of urgency.

The church was closed on 1st. May 1996. The closing of the church while the roof replacement was in progress provided an opportunity to do work on the interior. The four pillars obstructing the Sanctuary were removed to provide space around the altar. The clear span steel roof trusses made this possible. The back of the church was re-designed and extended forward to make this area more accessible and more welcoming. It provided better use of space particularly for a Shrine to Our Lady, the Patron of the Church. The overall work was costed at upwards of a million pounds. St. Mary's Church has served the generations of Mallow people since it was built two centuries ago. It is held in great affection by its parishioners.