The diocese is considered to be one of the epicentres[1] of the Catholic sexual abuse scandal in Australia, with scores of priests and religious brothers convicted of crimes against children.

Two senior members of the diocese, Father Thomas Brennan[2] and Brother William Wade,[3] have also been convicted of concealing child sexual abuse.

[4] The three most notable priests assigned to the Hunter Region, Therry, Dowling and Lynch, strived to build churches, schools and establish Catholic parishes.

The 1838 date coincided with the coronation of Queen Victoria and the Victorian era which included the age of steam driven locomotion.

The chapel was completed in 1841 and replaced by the current sandstone building in 1860 which Archbishop Polding blessed and dedicated to St Joseph on 19 Feb 1860.

[7] During 1840 and 1845 Archbishop Bede Polding visited the whole Hunter Valley and laid foundation stones for churches at Wollombi and St John's at Campbell's Hill.

Some of the early history involving Polding is published in 2 volumes with the title "Benedictine Pioneers in Australia" by Birt.

By a papal brief dated 27 May 1847, the Titular See of East Maitland was created with the Most Reverend Charles Henry Davis nominated as bishop.

In July 1933, Bishop Edmund Gleeson CSsR officially announced that the Catholic Hall in Maitland would be converted to a pro-cathedral suitable as a place of worship.

In 1948, the Newcastle and Maitland Catholic Sentinel published a number of articles on the occasion of the consecration of Auxiliary Bishop Toohey.

Discussions were then held and it was decided to convert the pro-cathedral to its former use as a hall and to reopen St John's as a chapel for the Central Maitland area.

On 24 June 1994, Bishop Leo Clarke celebrated a Dedication of a Church service and thus St John's became a chapel for the area.

See footnote:[14] The following individuals have been elected as Roman Catholic Bishop of Maitland:[15] The following individuals have been elected as Roman Catholic Bishop of Maitland-Newcastle:[15] Sacred Heart Cathedral in Hamilton acts as both the Hamilton parish church and the cathedral for the Diocese of Maitland-Newcastle.

[23][24] In September 2021, following Wilson's successful appeal, the fourth volume of the 2014 Special Commission of Inquiry into allegations of cover-up of sexual abuse claims in the Diocese of Maitland-Newcastle found that Archbishop Wilson was an "unsatisfactory and unimpressive witness" and that he gave evidence the commissioners considered untruthful, self-serving and implausible.

In pleading guilty, Wade became the first senior Catholic in Australia to admit to concealing child sex crimes.