Bishop James Quinn arrived in the diocese in 1861. Bishop Quinn began his first visit of the diocese accompanied by Father Renehan and Father Tissot, who also had recently arrived. They left Brisbane on the steamer Clarence on 23 July 1861, and two days later arrived in Maryborough. Fr. Tissot remained in Maryborough and became its first resident priest.
1852: First Mass in Maryborough.
1852: Home of Sergeant (constable) William McAdam, at Baddow.
1858: Wooden church/school. A school house was built on the present presbytery site in early 1858. Mass was celebrated here when priests visited.
On 15 July 18, it transferred from James Cleary to Arch Quinn.
On 29 July 1869, the foundation stone for the new church was laid.
Between 1884 and 1885, St Mary's was extended. The architect was F. D. G. Stanley.
The extensions were blessed 10 May 1885 by Bishop Dunne.
In May 1887, plans were drawn for the first presbytery.
On Sunday, 2 September 1888, Archbishop Duhig blessed and opened the Christian Brothers school. This school was amalgamated in 1979 with the Mercy Sisters' girls' secondary school to form the new "St Mary's College".
In 1888, the parish established a secondary boys school, inviting the Christian brothers to staff the college on its present site in 1888. (In 1979 the college became co-educational by the amalgamation with the Sisters of Mercy's St. Mary's high school for girls established on the site now occupied by St. Mary's primary.
On 22 March 1936, a second extension was added to the parish. The work included relocating the entrance to Adelaide St and adding a chancel. The architect was P. O. E. Hawkes and construction was carried out by H. G. Neilsen. After its completion on Sunday November 29, 1936, it was blessed by Bishop Duhig.
In 1936 a large stained glass window designed by William Bustard (1894–1973) and created by R. S. Exton and Co of Brisbane, was donated by the Corser brothers.
The stained glass window above the high altar was donated by Mr. Stellmach.
In 1958 Aramara became part of the parish. The church in Aramara was built, blessed and opened in 1950. It was the only church in the parish with a spire.
In 1972 it was decided that a new presbytery and hall were to be built. The work was carried out the following year and was blessed on October 21, 1973 by Arch Rush. Lyons who retired in May 1978.
In 1977 the wooden flooring was replaced with concrete.
Between 1989 and 1991, the organ underwent a full restoration.
On 4 August 1991 it was rededicated.
On 9 February 1993 the church was restored by Bellero Constructions with architectural designs by Hurst and Harris Pty Ltd.
In 1994 the church was declared a heritage building.
On 24 May 2000 a jubilee wall hanging was unveiled with a cabinet crafted by Brian White and his sons, Chris and Lucas. The cabinet was funded by the Gambling Community Benefit Fund.