[1] Following completion of the new St Monica's Cathedral, the building was deconsecrated as a church and has subsequently been repurposed as offices for the Diocese of Cairns and local parish.

In the same year the area from Cardwell to Cape York was separated from the Roman Catholic Diocese of Brisbane as the Pro-Vicariate of North Queensland.

In 1884, three Irish Augustinian fathers took charge of the Pro-Vicariate, establishing a priory at Cooktown, and in 1885 they founded the parish of St Monica's at Cairns.

In the interim, mass was held at the Palace Picture Theatre, and the convent school was conducted at the Irish Association's Hibernian Hall.

The contract was let to Cairns builder Michael Garvey, who completed the large, reinforced concrete building, officially opened on 16 October 1927, in about 7 months.

The effects of the February 1927 cyclone, followed almost immediately by flood damage, a severe trade depression, and waterfront disputes affecting the city's building industry, did not deter the predominantly working-class Catholic community of Cairns from raising within 8 months nearly £5,000 toward the re-construction.

The local parish priest, Father Phelan, raised a working-bee of 40 men who for months gave their spare time to clearing the debris of the church and school destroyed in the February cyclone.

[1] St Monica's Church and School was erected during the third major phase of Cairns' development, which saw the city boom in the 1920s and 1930s.

The Cairns hinterland Soldier Settlement Schemes of the 1920s, the completion of the North Coast rail link to Brisbane in 1924, the continued success of the local sugar industry, the expansion of wharf facilities, the extensive re-building necessitated by a spate of cyclones in the 1920s and the poor condition of earlier timber structures, combined to produce unprecedented building activity in Cairns.

The altar and Bishop's Chair were removed to the new cathedral and a stage was erected at the southern end of the former nave, which currently accommodates St Monica's School gymnasium.

[1] St Monica's Old Cathedral, located at the corner of Lake and Minnie Streets, is a two-storeyed, reinforced concrete building with timber floors and gabled roof structure.

At the top of the main stair are located double entrance doors which have a raised stepped plain pediment with Celtic cross supported on piers with Doric-styled half capitals.

[1] At the top of the main stair are double entrance doors which have a raised stepped plain pediment with Celtic cross supported on piers with Doric styled half capitals.

Access to the first floor was originally via a pair of timber dog leg stairs on the south elevation from Lake Street.

At ground floor level on the southern and northern elevations the segmental arched colonnades have been infilled with aluminium joinery.

East elevation has a matching gable to west end, with small lancet windows at high level between squared piers.

At the western end of each aisle are located double entrance doors with semi-circular heads that open out to the double-storeyed porticos.