The site was opened by Finance Minister Richard Hu on 1 March 1993, the 107th anniversary of the school's founding by Bishop William Fitzjames Oldham.

[2] ACS was founded on 1 March 1886 by Bishop William Fitzjames Oldham as an extension of the Methodist Church in Singapore.

Between 1914 and 1920, led by Reverend J. S. Nagle, the school introduced regular religious services and physical education classes.

He set up "X" and "Y" classes, each with different levels of difficulty, for students who had missed years of their education due to the Occupation.

In 1986, ACS celebrated its centenary with the publication of a hardback history of the school entitled Hearts, Hopes and Aims.

[citation needed] ACSP moved out of the Coleman Street campus in 1994; in its place now are the National Archives.

Independent schools are allowed to be privately funded and subject to less government regulation in setting out their curriculum.

The boarding facility soon expanded and moved into ever-larger premises, first in Bellevue at Oldham Lane, then to Dunearn House at Barker Road.

[3] The first principal of the independent school was Lawrence Chia, an associate professor of chemistry at the National University of Singapore and a Presbyterian elder.

In the GCE 'Ordinary' level examinations, ACS(I) had been ranked in the top 15 institutions in Singapore for a number of years since 1995.

[8] In 2010, 27 students worldwide were reported to have achieved the perfect score, of whom 13 came from the ACS(I) November 2009 examination cohort.

[14] In 2005, three other benefactors of the school were honoured by having houses named after them: these were Lee Seng Gee, Shaw Vee Meng and Tan Chin Tuan.

Established in 1994, the ACS (Independent) Boarding School houses around 500 students, mostly overseas scholars from the People's Republic of China, Indonesia, Vietnam, Malaysia, and India.

[16] Resident staff live alongside the students and provide a balance of academic and pastoral support.

It has been The Straits Times' Top School in Sports (Boys) in an almost unbroken streak since this title was first awarded, from 1996 to 2009.

ACS (Independent) holds the record of having the largest amount of Uniformed Groups in a single school.

ACS(I) emerged National Champions in 1998, 2005 and 2013 as well as 1st Runner-Up in 2004, 2006 and 2016 in the Singapore Secondary Schools Debating Championships.

At the national championships for pre-university levels organised by the Singapore Ministry of Education, ACS(I) emerged champions in 2010 and 2018 as well as 1st Runner-Up in 2012, 2014 and 2019.

The Orchestra achieved two Gold with Honours awards at the 2007 SYF competition, for both its Secondary and College String groups.

It also collaborated with the Singapore Armed Forces Central Band in March 2007, and was the featured orchestra in the 2007 HSBC Young Talents' Concert.

[40] In 2006, the band took part in the 17th Australian International Music Festival in Sydney, Australia, attaining a Gold Award.

Dance Venia, established in 2005, won the Gold with Honours Award at the Singapore Youth Festival Central Judging 2009 during their first participation in the event.