St Mary's accepted any student who wished to attend if they respected Catholicism.

Two main sources of students were Catholic pupils from two Catholic primary schools - St Mary's on Wellington Street in East Marsh, and St Joseph's on Philip Avenue in Cleethorpes.

In 1965 a new Secondary School was opened and was situated in the middle of the Nunsthorpe council estate in west Grimsby.

It closed on 20 July 2010, merging with Matthew Humberstone school to become St Andrew's College in September 2010.

There is also St Pius X catholic church [2] on Chelmsford Avenue in Grange, just north of the school.