It was initially designed by Charles Tiffin with later additions and alterations by Francis Drummond Greville Stanley and POE Hawkes.

In 1850 Surveyor, Hugh Roland Labatt arrived in Maryborough with instructions to "examine the River Mary...to suggest ...the best site or sites for the laying out of the town, having regard to the convenience of shipping on one hand and internal communication on the other...also...point out the spots desirable as reserves for public building, church, quay and for places for public recreation."

The timber building was erected principally as a school house, but used as a service centre when Hanley's replacement, Dean Rigby visited Maryborough.

Bishop James Quinn was appointed and he arrived in his diocese in 1861 and immediately made plans to visit the populated areas, including Maryborough.

The services of Brisbane architect, Charles Tiffin were procured to design the new brick church and the foundation stone was laid on 29 July 1869.

[2] St Mary's Roman Catholic Church, as it became known, was completed and opened at a service conducted by Father Tissot on 4 February 1872.

Father Tissot landscaped the grounds surrounding the church and provided the a chancel screen and other timber panelling carved by himself.

A new set of Stations of the Cross from Lyons, described as oleographs or coloured lithographs printed with oil paints, were framed in gold.

[2] During the nineteenth century the Roman Catholic Church in Maryborough continued to grow with several outbranches of the parish established in surrounding areas.

A cock was added to the western gable of the church reflecting the French ties of Monsignor MacCarthy, the then parish priest.

A section of the timber floor of the body of the church was replaced with concrete in 1979, followed by work in 1980 to stabilise foundations in the north western corner.

The complex comprises the stuccoed masonry church, stone and concrete grotto, and two modern steel and canvas shelters.

Around the altar the order of architecture changes to classical and, as a continuation of the nave arcade, Corinthian columns support an entablature to create the chancel space.

On the entablature are painted, in relief lettering, several religions phrases in Latin, and this writing continues around the cornice line of the transepts at this end of the building.

[2] St Marys Roman Catholic Church was listed on the Queensland Heritage Register on 21 October 1992 having satisfied the following criteria.

St Mary's has aesthetic and architectural merit as the work of a group of talented architects, forming a well composed building on a prominent Maryborough site.

The building features fine craftsmanship, particularly the marble high altar, stained glass windows, Stations of the Cross and joinery.