St John's has a clearly established Catholic ethos which is reflected in our Mission Statement:

At St John's College, we encourage the entire school community, as children of God, to realise their potential and be the best they can be.  

We aim to inspire and advance independent, critical thinking; creating curiosity and wonder for learning in its broadest sense.

Using our Christian values that draw upon the teachings of the Catholic Church, we love and cherish each other, celebrating our similarities and respecting our differences.  We enrich pupils’ experiences by providing equal opportunities that promote a deep respect for everyone, regardless of gender, race, creed or ability.

 We strive for happiness in all that we do; the family values of respect, compassion and security are at the heart of who we are.  We rejoice in preparing our children for life beyond St John’s, nurturing the desire and ability to have a positive impact as global citizens.

The school welcomes children from a wide range of ethnicities and backgrounds and provides a broad education to every pupil. Religious teaching at St John’s is informed by the rich cultural heritage of Christianity but also recognises that many of our pupils come from homes that are not Christian and often share a variety of faiths and traditions.  The high degree of harmony created by the school's ethos has impressed Estyn inspectors and this has been achieved by a sensitive and inclusive approach in which all pupils take part in corporate gatherings which are mainly Catholic in character but which respect and celebrate other traditions.

The study of Catholicism and Judaism at GCSE and Buddhism at A level is available to any student who wishes to pursue Religious Studies, and this is sometimes combined with the academic study of Philosophy.  

The Chaplaincy team exists to promote and foster the spiritual lives of the pupils by providing opportunities for worship, charitable work and education.