MG David Neo enlisted in the Singapore Armed Forces (SAF) in 1996. He is a Commando Officer by vocation, and served his junior command tours in the Commando Formation. He was subsequently Commanding Officer of First Battalion, Singapore Guards, Commander of 2nd Singapore Infantry Brigade and Commander, 3rd Singapore Division. He also served as the SAF's Director of Joint Operations (J3), where he oversaw the SAF's contributions to the national fight against COVID-19. MG Neo attended the Indonesian Army Command and Staff College (SESKOAD) in Bandung, Indonesia where he won both the Best Foreign Student and Best Thesis awards. He is also a graduate of the United States Army Ranger School.
MG Neo held various key appointments in the Ministry of Defence. He was Deputy Secretary (Technology), where he developed key technology, acquisition, procurement and logistics policies. As Future Systems and Technology Architect, he led MINDEF's research and development masterplanning, and advanced defence research priorities. As Head of the Joint Plans and Transformation Department of the SAF (J5) and Deputy Assistant Chief of General Staff (Plans) of the Army, he oversaw Strategic Planning, Capability Development and Resource Management.
MG Neo was awarded the SAF Merit Scholarship and graduated with a Bachelor of Science in Electrical Engineering (Honours) and Bachelor of Arts in Economics (Distinction) from University of Illinois, Urbana-Champaign and a Masters in Operations Research from Stanford University, USA. He was also awarded the SAF Overseas Postgraduate Scholarship and Lee Kuan Yew Scholarship in 2012, and graduated with a Masters of Business Administration as a Sloan Fellow of the Massachusetts Institute of Technology.
In addition to his military appointments, MG Neo was the Programme Director of the Pioneer Generation Office, and the founding Group Chief of the Silver Generation Office in 2018. He also served as the Chairman of the SICUS committee, overseeing security and spectator management of National Day Parade 2008, and as Chairman of the Show Committee, overseeing the conceptualisation and organisation of the Show Segment of National Day Parade 2014. MG Neo also served as a director on the boards of several agencies, such as Defence Science and Technology Agency, Singapore Polytechnic, Temasek Defence Systems Institute, Advanced Material Engineering Pte Ltd, and Cap Vista Pte Ltd.