St. James Church is situated off the Main Street overlooking the town park and the River Blackwater. Mallow's Church of Ireland is a typical example of an early 19th century building. The design is Gothic and is a limestone construction with cut stone buttressed corners and painted arched doors and windows. The Church was built on land provided by the Jephson family of Mallow Castle. It is adjacent to the old St. Anne's Church and graveyard. Its impressive spire is a focal point over a wide area. Though not in the more usual cruciform design, its regular shape is an imposing structure. Internally the Gothic style is evident. Its pointed arched roof structure and stained glass windows dominate. The dimensions of the Church are: length 120ft., width 50ft., height to eve 23ft., to apex 35ft., spire 120ft.

St. James Church was consecrated and opened in 1824. It replaced St. Anne's Church which had been damaged in the Williamite Wars and by 1817 was thought to be beyond repair. On the 29th August 1818 a contract was signed to build a new Church. The contract price was £3,700 stg. Rector of the period was Rev. Nicholas Wrixon and Church Wardens were John Gardiner and Richard Barrett. A condition of the contract was that local tradesmen and labourers be employed in preference to any others provided that they were as good and worked at the same rates. The builders were James and George Richard Pain, Architects, operating in Cork and Limerick. The Pain brothers were born in England and were apprenticed to John Nash, Architect, London.

In 1816 Nash designed Loughcutra Castle in Co. Galway for Lord Gort and the Pain brothers were recommended as builders. As a result they were appointed official architects/builders for the board of First Fruits, a body responsible for the construction of Church of Ireland buildings from the late 18th century until its duties were taken over by the Ecclesiastical Commissioners in 1833. This appointment was for the province of Munster and other Churches built by them include Buttevant, Midleton, Carrigaline and Mitchelstown.

They also designed the Spa House. The capacity of the Church was originally 800. Some years later old side galleries were removed and ancient square pews were replaced by modern ones. The floor was tiled, stained glass windows were put in, gas and hot water heating were installed. In 1892 the capacity of the Church was 464. In 1875 a new organ was installed by Ms. Foster and Andrews and the Ecclesiastical Commissioners awarded an annual grant of £20 for the pianist. This organ was installed in what was originally the Church Warden's room. Electricity was installed in 1931.

The reduction in the capacity of the Church coincided with a reduction in the number of Church of Ireland families. In the 1830s there were approx. 1,000 families in the Mallow area and by 1875 this was reduced to around 450. Part of this could be attributed to the Famine and some could also be due to the reduction of military personnel stationed in the town.

A feature of Churches designed by the Pain brothers and of Churches in general built around that time was the importance placed on the entrance gateway which was usually designed to complement the building. In this regard St. James's was no exception. The cut limestone piers and impressive iron gates were originally on the Main Street but were re-located to their present position by the Urban District Council in 1983. There is no bell in St. James's, the bell of St. Anne's is used up to the present day.

There was an exchange of bells between St. Mary's and St. Anne's. The present bell in St. Mary's was originally mounted in St. Anne's and came to St. Mary's when the campanile was first erected, the old bell suspended on irons was affected by the resonance from the limestone structure, the bell at St. Anne's was found to be suitable for the campanile and so an exchange took place. The old bell from St. Mary's transferred to St. Anne's belfry where it worked perfectly and is still rung for service to this day.