The first Catholic Church in Lambton opened in November 1871, about 5 months after the Borough of Lambton/Jesmond was incorporated by the NSW Parliament on the 24th June. The church was used as a school during the week, while at weekends Mass was celebrated. This wooden structure was built on the site of the present two story brick building abutting DeVitre Street, predating the creation of Lambton parish in 1873.

Schooling may have begun before 1871 to cater for the miners' children after a mine was opened in 1863. The Newcastle Chronicle records (6th July 1878) show that a Mr Maloney had been appointed to Hamilton Catholic School after three years at Lambton (1875-1878). At this time, one third of the children attending the school were Protestants. In January 1883, Mother Mary Stanislaus Kenny, the superior of a band of nine Sisters of Mercy who came from Ennis in Ireland, established a convent in Lambton. These Sisters arrived in Singleton in 1875, responding to a request from Bishop Murray for sisters to establish Catholic schools in the diocese.

Initially, the Mercy sisters lived in a small house a few allotments away, while a colonial house near the school was converted into a convent. The sisters taught in the school/church in Lambton and some travelled to Wallsend each day to teach in the little stone church on the hill. In 1929, a new convent was opened on the site of the former one, facing Dickson Street. As the demand increased, more sisters came to Lambton. At one point there were fifteen Mercy nuns living in the convent, some sleeping on the balcony upstairs.