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 celebrated the school's 105th Anniversary on 5th October. On that day, the new teaching block and the new Heritage Gallery were officially opened.