Mater Group was formed in 2016 by aligning Mater Health, Mater Education, Mater Research and Mater Foundation under a single, unified banner. Mater provides care for some 500,000 patients each year. Mater was established in 1906 by the Sisters of Mercy. In 2002, Mater became an incorporated body, charged with the responsibility to continue the Mission of the Sisters of Mercy to "offer compassionate service to the sick and needy".

The Sisters of Mercy is a religious institute for women in the Roman Catholic Church. It was founded in 1831 in Dublin, Ireland, by Catherine McAuley. As of 2019, the institute has about 6200 sisters worldwide, organized into a number of independent congregations. They also started many education and health care facilities around the world.