The Cathedral High School crest is a testament to strong Catholic faith and dedication to scholarly activities that the school community possesses. The crest contains a burning lamp, an anchor, a heart, and a book with quill. These images respectively represent the virtues of faith, hope/fortitude, love/charity, and wisdom. A cross, representing the importance of our Catholic faith at the centre of our lives, sits in the middle of the crest.

The school motto, "Probitas et Scientia", located at the base of the crest is translated "Goodness/Uprightness and Knowledge". These are two words that we encourage all students and staff to integrate within their lives.