The modern parish of O'Callaghan's Mills, Kilkishen and Oatfield is made up largely of the old parishes of Killuran and Clonlea. It is an extensive parish stretching from near Bodyke to near Sixmilebridge.
One of its noted parish priests was a Fr Patrick Quaid who was ordained for Limerick diocese but transferred to Killaloe diocese. He was parish priest from 1841 until his retirement in 1875. He was said to have been a man of very compelling personality, a man of great influence with the then ruling classes and a fluent speaker of Irish. He obviously owned his own house as it is reported that on his retirement his successor, Denis Cleary, bought it from him for £400 on behalf of the parish. A prominent supporter of Repeal during the Famine years, he expended himself in mitigating the sufferings of his people and he became a proponent of Tenant Rights.
The construction of the present church of St Patrick at O'Callaghan's Mills was begun in March 1839. Maurice O'Connell of Kilgory laid the foundation stone, the first Mass was said in it the following Christmas and it was dedicated by Bishop Kennedy in March 1840. It was refurbished extensively in 1979 – 1980.
It is not known exactly when a church was first built at Kilkishen for the old Clonlea side of the parish, the best guess being about the first decade of the nineteenth century. Our first reference to the church comes from 1811 when a dispute between local families over who should have the seats nearest to the altar led to the outbreak of disorder and the calling out of the yeomanry. In 1865 Bishop Power dedicated the church following building work. It seems clear that what was in question was a large scale renovation that changed the dimensions of the existing building.
St Vincent de Paul church at Oatfield was built about 1830, in the pastorate of Fr Darby Tuohy. There is a tradition that the floor of this church was once used for threshing corn, but probably this tradition should be more properly associated with the thatched chapel that preceded it. During the night of the Big Wind in January 1839, the roof of the church was blown away, 'cleith, tuighe is scolb'. Following this the building was enlarged and the two transepts were added. The church was rededicated in May 1966 by Bishop Joseph Rodgers. The dedication to St Vincent de Paul commemorates the local tradition that two Vincentian priests who escaped from the Cromwellian siege of Limerick in 1651, ministered for several years in this part of the parish.