The Salesian Sisters are the College Trustees; they form part of a worldwide congregation also known as the Daughters of Mary Help of Christians. The Salesian Sisters were founded in 1872 by St John Bosco and St Mary Mazzarello and they follow the spirituality of St Francis of Sales.
In 1959, the Salesian Sisters moved northwards, to Liverpool-Gillmoss where they ran the infant school and taught catechism and organised out-of-school activities for the older children and moved the pre-noviciate training programmes for young women wishing to enter the congregation. From the convent in Gillmoss, the Sisters could see the site of their second community in Liverpool, at Croxteth, where the Archbishop had invited them to open a secondary school for girls. Mary Help of Christians High School was opened in 1965; this high school was later to become St John Bosco Arts College.