Short brought with him an endowment of £2,000 from the Society for Promoting Christian Knowledge with which he was expected establish an institution for the Church of England.

He intended to use the Trinity School as the basis for this institution and had his chaplain T. P. Wilson appointed as its Head Master.

[4] A similarly large endowment was contributed by William Allen, who through an early investment in the South Australian Mining Association had become wealthy.

George Henry Farr (1819–1904) arrived from England in July of that year and served as head master 1854–1879.

Beneath the shield is a scroll with the school's Latin motto "Pro Deo et Patria", which translates into English as "For God and Country".

To accommodate the growing student population five additional houses were founded: MacDermott, Woodcock, Young, Howard and Farr.

Through sporting, academic, musical, fundraising and other competitions throughout the year, the houses compete for the Sir George Murray Shield.

In 2021, St. Peter's College ranked equal 8th in South Australia and 358th nationally for academic achievement (including NAPLAN, ATAR, IBD).

[12] In 2010 The Age reported that St Peter's College ranked equal 7th among Australian schools based on the number of alumni who had received a top[note 1] Order of Australia honour.

St Peter's College, working with Martin Seligman and Lea Waters, has been instrumental in the development and implementation of PESA's positive education programs throughout Australia.

The main campus' facilities include seven ovals, a hockey pitch, ten tennis courts and two swimming pools.

It features mostly heritage architecture, such as "Palm House" (built for William Peacock), but also includes modern buildings.

[19] A somewhat common Adelaidean urban myth asserts that the Da Costa estate was intended to be given to the Catholic church rather than the Anglican, and that the funds were awarded to Saints after a supposed legal battle.

This myth has no basis in fact and most probably stems from misconceptions of da Costa's religion due to his Portuguese family name.

In addition, students have the opportunity to join the Exploration Society, which allows boys with a passion for outdoor activities to pursue more challenging ventures.

Activities include hiking, kayaking, rock-climbing, mountain bike touring and cross country skiing.

St Peter's College's exchange program has links with schools in Germany, France, China, South Africa, England, Switzerland, Mexico and Canada.