The church building was designed by William Kerr under T.G. Abercrombie of Paisley. Kerr was about 23 years of age at the time. The sanctuary lies on an east-west axis with a chancel to the east as is traditional. It is built of red sandstone from Locharbriggs and Corsehill in Early English Gothic style, a seven bay church with buttresses, a single aisle to the north and a 160 foot, three stage tower and spire, a session room and four bay hall to the south east. Among the most prominent features of the exterior are the large traceried windows, the statues of Moses and St. John on the west gable and the gargoyle at the south-east entrance. The church, along with the octagonal gatepiers, is a category A listed building. The final cost of the church, met by John Clark, was £30,000, the two manual Willis organ having been donated by his brother William. Mr. Clark made two main stipulations, that the church should be visible from the sea and that there should be no pillars to obscure the view of worshippers. This latter condition resulted in an intricate structure of roof timbers, comprising five principals of double timbers with tie and crown beams. Heavy struts spring from beautifully moulded and shafted capitals which terminate with carved bosses and support the hammer beams. These have intricately carved angelic figures on the ends, from whose hands are suspended the main lighting of the church. The chancel and transept ceilings are in the Gothic style, lined in wood with moulded ribs.
The walls are panelled by a 15 foot high dado of carved Austrian oak, topped by a finely detailed cornice. On the chancel panelling the text “Seek ye my face; Thy face, Lord, will I seek” is highlighted in gold. (Psalm 27:8) The Communion Table is also of carved oak, with the IHS monogram picked out in gold. The other church furnishings are of a later date.
The three communion chairs, the eagle lectern and the baptismal font are also in oak. An offering pedestal contains a bronze plate gifted by an African chief and brought to Largs by the famous missionary Mary Slessor of Calabar.
The War memorial is in the form of a bronze plaque and bears the names of church members who fell in the two World Wars together with appropriate regimental badges. A large tapestry worked by women of the congregation was dedicated in the church’s centenary year, 1992. Its principal image is the anchor, both the Christian symbol of hope and the trademark of John Clark.