1912-1917: Ai Tong School was established. Originally, the school with only 30 pupils, was housed in a Methodist Church at Boon Tat Street. The school was re-sited at 209, Telok Ayer Street in 1917.
1929: The Singapore Hokkien Huay Kuan took over the autonomy of the school.
1946: The old Gan Eng Seng School premises was rented to start a branch school. The enrolment increased to more than 1,600.
1956-1957: The main school moved to the Singapore Hokkien Huay Kuan building at 137, Telok Ayer Street. The school became a government-aided school in 1957.
1961: The enrolment of the main and branch school was approximately 2,360. This was the biggest enrolment achieved by the school.
1978-1981: Construction work for a new school building at Ang Mo Kio Ave 3 started in 1978. The new school building was officially declared open by the Parliamentary Secretary (Education) Mr Ho Kah Leong on 9 Oct 1981.
1990: The school became a SAP school. The pupils took English and Chinese as the first language.
1992-1993: The school was relocated to 100, Bright Hill Drive Singapore 579649, on 9 Jul 1992. The Minister of Foreign Affairs, Mr Wong Kan Seng, officiated at the Relocation Ceremony on 9 Jul 1993.
1998-2000: The extension block housing special rooms was completed. In 2000, it was officially opened by the chairman of the Singapore Hokkien Huay Kuan, Mr Wee Cho Yaw.
2002-2009: The school started on-site PRIME in Nov 2002. The project was completed in 2004. The Indoor Sports Hall was completed in 2009.
2012: Ai Tong celebrated its 100th anniversary. The school staged a musical, entitled "A Journey With Love", at Kallang Theatre on 29 June 2012. A charity dinner was hosted on 17 August 2012 with Minister for Education, Mr Heng Swee Keat, as the Guest-of-Honour. Funds were raised for Thong Chai Medical Institution and Ren Ci Hospital.
2013-2015: Ai Tong was awarded two Learning for Life Programmes (LLP) - Caring through Arts and Outdoor Education - to provide a holistic Education for the students.
2016: The school compound was expanded after PERI upgrading and Ai Tong School turned single session.
2017: Ai Tong will celebrate the school's 105th Anniversary on 5th October, which when read in Chinese is 10月5日. The number 105 is thus symbolic to this event. On this day, the new teaching block and the new Heritage Gallery will be officially opened.