Despite these intentions of the legislation, it was the Roman Catholic Bishop Quinn who, by mid-1861, had raised sufficient funds to open Grammar Schools in both Brisbane and Ipswich.

Amidst an outcry from the Protestant section of the community, Bishop Quinn was informed by the Executive Council of Queensland that the intention of the legislation was to establish Grammar Schools on strictly non-sectarian principles.

This decision may have been influenced by the fact that not a single member of either House of the Legislature in Queensland at the time was a Roman Catholic.

Trouble erupted when a resolution was put forward that members of each religious denomination be appointed to a committee to make preparations for the new Grammar School.

A member of the Roman Catholic group suggested that they would withdraw their funds if they did not get their own way – and the meeting ended in turmoil, with a brawl taking place.

In the week following this first meeting, newspapers reported clashes in the streets of Ipswich between Roman Catholics and the Protestants.

The Roman Catholic group promptly withdrew their financial support, and it would be March 1862 before the community of Ipswich would raise the £1000 required.

The first Board of Trustees, elected on 25 March 1862, called for plans and specifications to be submitted for the new school building.

Architect Benjamin Backhouse made the only submission, and after a small problem with his initial design was overcome (he had forgotten to make provision for toilets), the plan was accepted.

The original building (known as the Great Hall) was designed in a revival gothic style, and it was constructed by contractors John Ferguson and David McLaughlin.

[14] The School opened with 16 students, 4 staff and the inaugural Headmaster, Stuart Hawthorne, a graduate of the University of Sydney.

More growth was to follow, with the Manual Training facilities and an on-campus hospital added in 1967, biology block opened in 1970, the R.G.

The decade was to end in sadness, however, as Headmaster Alan Ladley died suddenly on the final school day of 1989.

In 2020, a new STEM building was added to facilitate the schools growing population of students in engineering, biology, physics and more.

Costing around $10 million and consisting of three storeys, the building include a lecture theatre, multiple science and engineering laboraties and other learning spaces, designated "study areas", and a balcony providing panoramic views of Ipswich and Western Brisbane.

Now included within the Igor Lapa Junior School is a full indoor sand volleyball pit, basketball hoops, and cricket pitches.

], the Board of Trustees approved expansion of the Prep buildings, and refurbishment of the remaining Tennis Court at Ipswich Grammar's main campus.

Eight new tennis courts were constructed at the Brassall grounds during the 2008 Christmas break for GPS competition and training for the students.

[29] In addition to representing Australia in athletics in Commonwealth Games and Olympic Games, IGS students and alumni have represented national teams in virtually every sport, most prominently in basketball, cricket, rugby union, rugby league, soccer, swimming, and water polo.