Great Southern Grammar is an independent non-denominational Christian co-educational primary and secondary day and boarding school, located in the Great Southern regional town of Kalgan, Western Australia between the King River and the Kalgan River.

The campus has a total area of 58 hectares (144 acres)[3] bordered by Nanarup Road to the north, Oyster Harbour to the south, Johnston Creek to the west and the Kalgan River to the east.

Students attend the school predominantly from Albany and the Great Southern, but also from other parts of Australia and internationally, with a current boarding population of ~140.

In 2009 the school was ranked at number 10 in Western Australia, based on results of its Year 12 students.

[6] After opening in rented premises at Mount Melville in 1999 with 36 students, the school relocated to the Lower Kalgan campus in 2000.

[7] The new Middle School building, including new classrooms, music facilities and science laboratory was opened in 2009.

The new multi-purpose sports facility, partially funded by the Building the Education Revolution program, featuring two basketball courts and a synthetic surface, was completed and opened in June 2010 during the school's Foundation Day ceremony.

The celebration of Great Southern Grammar's foundation is taken as a greater milestone within GSG and the GSG community with previous students, staff, principals and current students, staff and families with the support of special guests who make an impact on Great Southern Grammar and its development.

The four houses compete in interhouse competitions including swimming, athletics and cross country.

Ranging locations, year groups and activities, The school has many opportunities for students to engage with the environment around the Great Southern and beyond.

The school participates in many sports in the local leagues including soccer, netball, hockey and basketball.

The sporting uniform is navy blue and red, usually in horizontal stripes, although the design has changed through the years.

The school won two division shields in girls' A-grade hockey and boys' C-grade soccer.

The 2008 carnival saw the school represented in the same sports as the previous year with the inclusion of a girls' basketball and a speech and debating team.