Career
He was also a military historian at the National University of Singapore. Entering politics in 1988, Ong served the Bukit Batok Constituency for two terms, before the constituency became part of the Bukit Timah Group Representation Constituency in 1996, and the constituency becoming a part of the Jurong Group Representation Constituency in 2001. In 1991, Ong was appointed Parliamentary Secretary for Ministry of Home Affairs and Labour.
During his twenty years in politics, Ong also served as the Chairman for the Government Parliamentary Committees for Education, Defence and Foreign Affairs.
Ong was also known as a historian with several publications about World World War World War II
On 2 August 2008, Ong"s alma mater, Victoria School, named a student leadership award after Ong. Called the Doctor Ong Chit Chung Leadership Award, it is awarded to high-performing students in the school.
Ong"s old Chief Librarian badge that was used when he was still in Victoria School, was presented by Ong"s widow to the principal Low Engineer Teong, and was later added to the collection in the school"s heritage centre. The Ong Chit Chung Memorial Scholarship is also named after him.