Major-General Neo joined the Singapore Armed Forces(SAF) in March 1983 and was a SAF (Overseas) Scholar in 1984. In the course of his military career, he has held among others, the appointments of Chief of Staff, Joint Staff cum Director, Joint Operations and Planning Directorate (JOPD); Commander, Army Training and Doctrine Command; Commander, 9th Division; Assistant Chief of the General Staff (Operations); Assistant Chief of the General Staff (Personnel); Commander, 7th Singapore Infantry Brigade; and Commanding Officer, 1st Battalion, Singapore Guards.
Major General (then Brigadier General) Neo Kian Hong was appointed as the new Chief of Army in the SAF on the 20th of March, 2007.
Major-General Neo also served as the SAF's contingent commander for INTERFET (International Force for East Timor) in 1999, and played a pivotal role in establishing the national contact and tracing system during the SARS crisis in 2003. Major-General Neo attended the Indonesian Army Command and Staff Course (SESKOAD) in 1994. He holds a Bachelor of Engineering Degree (Hons 2nd Upper) (Electrical Engineering, Electronic Engineering) from King's College London, UK; as well as a Master of Science Degree (Management of Technology) from the Massachusetts Institute of Technology, USA.