The present school was formed by the merger of the original St. Peter's Boys school and Merrow Grange, a Catholic girls school. St Peter's School was founded by Archbishop Amigo in 1947 and named St. Peter's his patron saint. It was housed in two buildings. One was the present site on Horseshoe Lane East and the other in Horseshoe Lane West. The Headmaster and a number of the teachers were Diocesan Priests. Merrow Grange was on the corner of Horseshoe Lane East and the Epsom Road. In October 1945 it was purchased by the Ladies of Mary and became an independent girls school called Merrow Grange. It was a Convent School run by the Daughters of Mary and Joseph, a foundation which continues to fund educational project in many other geographic areas. In 1971 by agreement the Diocese took over the running of the Girls' School to form a coeducational school. The larger mixed institution's newly constituted governors' board, with teacher consultation, named itself St Peter's and Merrow Grange School and later for some years St Peter's Catholic Comprehensive School. In May 2010 the school adopted the name St. Peter's Catholic School.
Facilities
Theatre
In the early 2010s the school expended savings and received grants, such as from the registered charity named after Humphrey Richardson Taylor for music activities in education, to open its 'St Cecilia's Theatre'. after the :en:Saint Cecilia|Patron Saint of Music. As of now, the theatre has been built and is being used for productions put on by Drama Students and regular students.
Inspection reports
The school was inspected by the Diocesan Education Lead and Associate Inspectors in November 2013, on a four to five yearly cycle. Their report rated the school in the highest of their four categories, outstanding, and found: The school was inspected by Ofsted Inspectors in February 2013 on its varying cycles based on the previous findings. The government-established inspectorate rated the school in the highest of their four categories, outstanding across each of its four measures: achievement of pupils; quality of teaching; behaviour of pupils; leadership and management. Its summary of findings commenced as follows:
Sixth Form Centre
The school's enlarged sixth form centre opened in September 2011. The sixth form currently consists of 200 students, and benefits from a means-tested 16–19 bursary fund for bursaries. To prepare for further study or workplace positions the centre enabling students to take AS and A2 tutor-directed and assisted courses in many subjects.
Structural Incidents
In January of 2018 the new school building which was in construction caught on fire due to what was believed to be an incident with a gas cylinder. Get Surrey reported that "Flames could be seen rising from the side of the school, which is currently under construction.". It was also reported by the news company Get Surrey that "Firefighters had been called to St Peter's Catholic School, in Horseshoe Lane East, to tackle the blaze."
Catchment and key admissions factors
The school's geographical catchment areas are drawn and redrawn regularly, taking into account demand and the other admissions' criteria. Influencing redrawing and admissions policy are attendance at or residence within any of the nine parishes forming the Guildford Deanery and the ease to transportation to the school, relative to other schools. Four primary schools form with St Peter's its closest 'Family of Schools', preferential feeder schools, and are variously spread across the majority of the Boroughs of Guildford and Waverley forming the approximate south-west quarter of the county, numbered '6' and '7' in the map shown to the right.
