St Columba’s has a Vertical House Structure, which is an important part of life at the College. There are seven Houses. Each proudly bears the name of their patron, women of faith who are inextricably linked to the heritage of the College, with their own stories that epitomise the College’s motto ‘faithful and strong’. These women provide fitting role models for the future generations of young women at St. Columba’s.

The College has chosen the first five Sisters of Charity who bravely sets sail for Australia from Ireland in 1838: Sister Mary John Cahill, Sister Mary de Sales O’Brien, Sister Mary Xavier Williams, Sister Mary Lawrence Cater, Sister Mary Baptist de Lacy. The first St Columba's College Principal, Mother Mary Ursula Bruton and the first Australian born Sister of Charity, Sister Mary Xavier Cunningham make up the seven. Each House is known by the surname of these courageous and audacious women.

Each House is split into three Junior (Year 7 – 9) and three Senior (Year 10 - 12) House Groups. These are intimate House Groups of approximately 24 students, led by a House Teacher. Students remain in the one House throughout their time at St. Columba’s.

Students remain in the Junior House Group for Years 7 - 9 before moving to the twin Senior House Group for Years 10 – 12. This provides the opportunity for students, staff and parents to foster relationships with each other. The continuity of remaining in a House Group provides parents with one key point of contact for the wellbeing of their daughters over a three-year period. Simultaneously the House Teacher benefits from dealing with the same families over a sustained period.

Students benefit from greater diversity within a pastoral care group as each year the older students are replaced by a younger group. The House System offers many opportunities for students to gain experiences of leadership, and the need for mentoring of younger students is implicit in the structure. This allows for multiple sources of support and encouragement as students form new relationships.

Students identify themselves as a member of their House on a daily basis through morning House Group. The House is in effect their ‘home’ within the school, both in a physical and communal sense.

Throughout the year student experience many co-curricular and whole school activities through their membership of a House. This includes a range of sporting, cultural and other events where each House competes for points. Students attend House Assemblies to plan and organise these activities. At the end of the year, ‘The House of the Year’ is awarded to the House with the most points.

House logos: Bruton, Cahill, Cater, Cunningham, de Lacy, O'Brien and Williams