The Theatre Royal is one of the oldest theatres in Christchurch still in use as a theatre. It was built between 1906 and 1908 and was the third theatre of this name to be built in Gloucester Street.

In 1861 Christchurch's first theatre, the Canterbury Music Hall, was built on a site across the road from the current Theatre Royal. The Canterbury Music Hall was renamed the Theatre Royal in 1866 and the building was replaced by another on the same site in 1876. This building of 1876 is still standing, although no longer used as a theatre, and is also registered by the New Zealand Historic Places Trust/Pouhere Taonga.

The third Theatre Royal, the subject of this registration, was designed by the Luttrell brothers, Alfred and Sidney, who arrived in New Zealand in 1902. Their chief contribution to New Zealand architecture was in the introduction of the Chicago 'skyscraper' style, as seen in the New Zealand Express Company buildings in Christchurch (1905-1907) and Dunedin (1908-1910). They also specialised in the design of race course grandstands and worked as unofficial diocesan architects for the Roman Catholic Church in Canterbury. The theatre they designed in Gloucester Street, for a syndicate headed by American-born J.C. Williamson (1845-1913), differed from their contemporary work by looking back to the Victorian love of decoration, as expressed on the theatre's ornate façade, instead of a bolder Edwardian or American style. The theatre also had an elaborate cast iron verandah, which gave it something of an Australian feel. This was removed in 1928 and replaced by a plain verandah suspended from the first floor. The acoustics of the theatre have always been acknowledged to be superb.

Initially the Theatre Royal was used for live theatre, although it did show motion pictures occasionally. In 1928 it was refitted as a cinema and for some time that became its primary function. It was run by Christchurch Cinemas from 1941 to 1956. From the mid 1950s the theatre was again used for live performances and over the years it hosted wrestling matches, musical performances and opera. The Theatre Royal began to lose customers and acts from 1972 and was threatened with demolition. In 1980 it was purchased by the Theatre Royal Charitable Foundation, a trust established by local people who wished to see the theatre preserved. Today it is still used as a theatre.

The Theatre Royal is significant as one of the earliest theatres in Christchurch and as part of the history of theatre in Canterbury, particularly in conjunction with its earlier namesake across the street. Within the wider history of New Zealand cinema the Theatre Royal is one of a number of cinemas built or taken over by the J.C. Williamson Picture Corporation. The theatre is a fine example of the Luttrells' architectural skill and diversity and the building forms an important part of the townscape of Gloucester Street. The establishment of a trust to buy the building in 1980 indicates the public feeling for the building.

[The following information describing the situation of the building following the Canterbury earthquakes of 2010-11 is from the Isaac Theatre Royal website: http://isaactheatreroyal.co.nz/our-history/theatre-history/ (accessed 27 July 2017):
'Mercifully our Grand Old Lady of Christchurch Theatre has survived the massive earthquake and considerable aftershocks that rocked the city in 2010 and 2011. The Theatre re-opened on 17 November 2014. The project was significantly more elaborate in design and complexity of construction than originally estimated with the Theatre essentially being rebuilt from Façade to Proscenium Arch. The rebuild and restoration had significant challenges throughout, making it one of the most intricate building projects in the earthquake damaged Christchurch CBD with an overall rebuild cost of NZ$40M. Some extensive earthquake strengthening work undertaken in 1998/99 has without doubt saved this 100 year old Heritage building from complete collapse but some significant deconstruction was required to secure and protect the key interior and exterior heritage elements.'

[In 2016 the Isaac Theatre Royal was the winner of the 'Public Realm - Saved and Restored' category of the Canterbury Heritage Awards, in recognition of the rebuild and restoration work carried out on the building.]