Singh received the Singapore Armed Forces Overseas Training Award (Academic) in 1983.

He was commissioned as a signals officer in December 1986 and served in active duty with the United Nations Iraq–Kuwait Observation Mission (UNIKOM) in Kuwait in 1991.

In 1995, he attended the United States Army Command and General Staff College at Fort Leavenworth.

[2] In 2011, Singh was recalled back to active service and succeeded Chan Chun Sing as the Chief of Army on 25 March 2011 and held this appointment until 21 March 2014, when he was succeeded by Perry Lim.

[1][3] Singh, who is of Punjabi Indian descent and a Sikh by religion, is the first non-Chinese Singaporean to serve as the Chief of Army since 1982.