The Rev. Anthony Joseph O'Loughlin was the driving force behind the construction of the present church. He was originally a cabinet-maker, and carved an altar and reredos of St. Peter's Church in Brockville. He gave lectures in the communities around North Gower as a means of raising funds for the building of Holy Trinity.
The dressed stone for the church was quarried in Goulbourn Township, and brought to North Gower by members of the congregration. The rough stone, used for the foundation and walls, was brought from Hugh Moffat's farm in Marlborough and from the Leach farm in North Gower.
The cornerstone of the church was laid on June 25, 1879. It is on the east corner, under the Rector's Vestry. Nicholas Leach put copies of current newspapers in the niche of the stone.
The first Anglican church in North Gower was of frame construction, building date unknown. After the stone church was built, it was used as a carpenter's and joiner's shop by Robert Willis. It changed hands to Fred Lord and then to Robert Acton, and burned down in 1911.