On 14 August 1916, the Queensland Governor, Sir Hamilton Goold-Adams unveiled a war memorial with the names of 600 students who had enlisted.

[9] In 1921, Brigadier General Lachlan Chisholm Wilson, a former pupil, presented a field gun to the school, an Austrian-made 10.4 cm Feldkanone M. 15, which had been taken from the Ottoman Army by the Australian Light Horse at the Capture of Jenin in 1918.

During the mid-1990s, the school commenced work on the off-campus Northgate ovals, which now consist of six fields that are used for cricket, rugby union and soccer fixtures.

With the newly reformed Economics and Enterprise Club, students are gaining exciting experiences through external competitions such as YAA, Ecoman and ABW.

An array of other special-interest groups exist, including those which focus on Chess, Astronomy, Aviation, Christianity, Environmental aid, and Community Service.

The school offers a range of mainstream sporting activities, including cross country, track and field, rugby, football, basketball, tennis, cricket, gymnastics, debating, swimming, rowing, sailing, chess and volleyball within the GPS association of schools, as well as many others such as water polo, fencing and tae kwon-do.

in the early stages of GPS when competition with earlier established Ipswich Grammar began, Australian rules football was the chosen code.

The Indoor Sports Centre was officially opened by the Governor of Queensland, Major General Peter Arnison on 3 March 2000.

The centre, which is situated on the main campus, is home to a multi-purpose double basketball court sports hall (which can also accommodate three volleyball courts, six badminton courts, 12 fencing pistes as well as futsal), an aquatic centre with a 10-lane, 25m heated swimming pool, a gymnasium featuring a deep foam pit, parallel bars and rings and a spectator area with seating for 150 people during sporting events, an indoor cricket net, as well as a weights room and theory rooms and amenities.

Work commenced on the Northgate Playing Fields in the mid-1990s, which now have six ovals, accommodating Cricket, Rugby union, Soccer and Australian Rules Football fixtures.

The playing fields were used by the Australian Cricket Team prior to the 2006/2007 Ashes campaign, where they trained with the school's First XI.

The school sends each form class from grades 8, 9 and 10 out to the campus to strengthen intra-class relationships and morale, as well as develop team-working and leadership skills.

Year 11 outdoor education leaders also attend the camp to build the relationship between the senior, and younger students.

The five-day programme includes such activities as rock-climbing, bushwalking, orienteering, canoeing, and a camp-out in the bush at the foot of a mountain.

The Lilley Centre is a centre located on the College Road side of the main campus (named after Premier and chairman of the Board of Trustees Sir Charles Lilley), and houses several classrooms equipped with learning technologies, a library, a lecture theatre (called 'The Forum') and a seniors' study room.

Two former students had allegedly lodged complaints about Lynch's conduct with then headmaster of the school, Maxwell Howell, in the early 1980s and the issue was quietly investigated.

[16] For failing to notify its insurer of the complaints made of Lynch, the school thus became liable for A$1.17 million in legal fees and compensation.

[16] Lynch was charged in January 1997 over the abuses perpetrated at both St Paul's School (where he was subsequently employed) and Brisbane Grammar.

6 ambulance crews were dispatched to the school, where 35 students experienced sore eyes and throats as well as minor breathing difficulties.