The life of our school began in 1871 when the Sisters of St Joseph arrived in Port Augusta to begin a primary school. (The sisters of St Joseph take their inspiration from Mary MacKillop (Mother Mary of the Cross) who, with Father Julian Tenison-Woods, founded the congregation in South Australia in 1866.)
In 1927 a primary/secondary school was established in Flinders Terrace, Port Augusta on the site which now accommodates the Wadlata Centre.
In 1971, the centenary year of the sisters' arrival, St Joseph's High School was opened in Dartmouth Street, Port Augusta. The whole school adopted the name ‘Caritas College’ in 1971 as a tribute to the 100 years of service by the Sisters of St Joseph. The motto of the Josephite school became ‘In Omnibus Caritas’ – in all things, love – to reflect the love of Christ as a motivating force within the school.
The present school was opened in 1983 on Woodforde Street campus to accommodate students from Reception to Year 9 and four years later students from 10-12 were relocated to the Woodforde Street site.
Since that time the school's facilities and resources have expanded rapidly to provide opportunities for an education in the Catholic/Christian tradition provided by a committed and professional staff.
In 2017 a $5.5M building project was completed which includes a Year 10 and 11 learning centre, STEM (Science, Technology, Engineering and Maths) labs, Languages room, Visual Arts Centre, and refurbished administration. This will provide rich, contextual learning with greater access to practical activities, thus enhancing learning opportunities.
To meet the needs of students from outlying areas, often quite distant from Port Augusta, MacKillop House was opened opposite the college in 1994 providing a boarding facility. The boarding house closed at the end of 2011 and in 2013 changed it's name to MacKillop Learning Centre delivering the Learn Through Play, Playgroup. (This program offers a playgroup for children 0 - 5 years along with opportunities for community adult education.)