There are two main categories of private schools in Australia: Catholic schools and Independent schools.

Private schools in Australia may be favoured for many reasons: prestige, and the social status of the 'old school tie'; better quality physical-infrastructure and more facilities (eg. playing fields, swimming pool, etc.), higher-paid teachers, a perceived higher quality of education; some schools offer the removal of the distractions of co-education; the presence of boarding facilities; or stricter discipline.

Private schools in Australia are still heavily government funded, although they are also more expensive than government schools.

Private schools may have a greater focus on sports and other associations than public schools.

Unlike most public schools, most Australian private school students are subject to strict dress codes.

Catholic schools

Catholic schools form the next largest sector after government schools, with around 21% of secondary enrolments. The Catholic system is also vast and accessible – sometimes even for those out of the habit of practising their faith. Most belong to a system like government schools, and attempt to provide Catholic education evenly across the states through mainly co-education schools. These schools are also known as systemic. Systemic Catholic schools are funded mainly by government and have low fees.

There are also a substantial number of independent Catholic schools, often single-sex, usually run by established religious orders, such as the Sisters of Mercy or the Christian Brothers. Independent Catholic school fees vary, ranging from low to high. However, fee concessions for Catholic families facing financial difficulty are quite common.

Catholic schools, both systemic and independent, proclaim strong religious motivations and most often the majority of their staff and students will be Catholics.

Independent schools

Independent schools make up the last sector and is the most popular one for boarders. Independent schools are non-government institutions that are generally not part of a system.

Although most are non-aligned, some of the best known independent schools also belong to the big, long-established religious foundations (Anglican, Methodist, Presbyterian) but in most cases they do not insist on their students’ religious allegiance. Many of the ‘grammars’ also fall in this category. They are usually expensive schools that tend to be up-market and traditional in style.

On the other hand, many independent schools are quite new, often small and not necessarily traditional at all.