[1] After Singapore gained independence in 1965, the school came under the purview of the Ministry of Education and was accorded the Special Assistance Plan (SAP) status in 1979.

As early as May 1913, Tan Kah Kee, a prominent businessman, proposed setting up a secondary school for Chinese boys in Singapore.

Tan's proposal was supported by the Tung Teh Reading Club and a dance troupe, claiming to have raised S$20,000 as funds for building the school.

On 21 March 1919, the Singapore Nanyang Overseas Chinese Middle School was formally opened at Niven Road with an enrolment of 78 students.

In the same year, Lee Kong Chian, son-in-law of Tan Kah Kee, became the chairperson of the school's management board, and he held the post until 1957.

On 13 May 1953, TCHS students made an impromptu march to the Singapore city centre in protest over arrests of their fellow schoolmates.

[3] The situation was finally defused after the Chairman of the Board of Directors, Lee Kong Chian, flew back from London and mediated a resolution between student leaders and the police.

[5] In 1967, a group of students attacked then-Vice Principal Teh Kim Fatt on the campus, prompting then-Prime Minister Lee Kuan Yew to visit him in the hospital.

The changes include the abolition of mid-year examinations in favour of camping trips for the school, as well as the introduction of numerous enrichment programmes in place of lessons.

[citation needed] Two days later, on 21st March, the school held a large dinner in front of the Clock Tower in celebration of TCHS' 80th anniversary of founding.

[citation needed] At the dinner, which was attended by alumnus and then-President Ong Teng Cheong, a statue of school founder Tan Kah Kee was erected.

The new scheme, which integrates four years of high school education and two years of pre-university education, allows students to skip the Singapore-Cambridge GCE Ordinary Level examination (typically taken by students in secondary four) and proceed to take the Singapore-Cambridge GCE Advanced Level examination at the end of the programme.