[2] St. Gabriel's School opened its doors on 3 June 1953 (costing S$175,000 with a government contribution of S$71,000) and stood at the junction of Hillside Drive and Upper Serangoon Road.

The school was officially declared open on 13 December that year by Michel Olcomendy, Bishop of the Diocese of Singapore and Malacca.

Under the leadership of Brother Adolphus, the class sat for the Overseas School Certificate Examinations (Cambridge) and achieved a high passing rate of 90%.

Some premises were converted into machine and electrical workshops to cater to the needs of pupils of SGSS and three neighbouring schools.

Leadership was passed on to Brother Edmund James in 1974 and Peter Tan was appointed Senior Assistant of the school.

The Brothers of St. Gabriel's were at the helm of the school for 30 years (1953–1983) before the leadership was passed on to lay principals in 1984.

[3] At present, the school teaches the default GCE 'O' and 'N' Level syllabus as outlined by the Ministry of Education.

[4][5] An early example of academic success for St. Gabriel's came in 1970 when the school attained 71% passes in the Senior Cambridge examination results.

[9] The school has also met the requirements for the Singapore Quality Class (SQC) for business excellence with effect from 31 January 2008.

Badminton nets are set up on the parade square, and the indoor sports hall is available for students wishing to play futsal.

There is an inter-class soccer tournament for Secondary 3, and the possibility of expanding this idea to other levels and sports was under consideration at the end of 2011.

This is in line with the St. Gabriel's Foundation's aim to forge a common identity for all Gabrielite institutions in the Southeast Asia region.

Coupled with peace is prosperity, which connotes not only the generation of wealth but also the integral development of human society.

Hard work embodied in diligence and perseverance leads one to achieve greater things in life.

For significant breaches of school discipline, the standard consequence is corporal punishment in the form of caning on the buttocks over clothing.

[23] Brother Emmanuel, principal of St Gabriel's from 1961 to 1963 and again from 1969 to 1974, has been described by the Catholic News as "a disciplinarian whose cane has graced the backsides of many boys".

[25] In 1970, seven or eight boys were found to be smoking cannabis, but the problem was stamped out with counselling, guidance and warnings, according to the principal.