The Singapore Army Intelligence was initially formed as the Department of Military Intelligence (DMI) on 9 February 1966 and located at Pearls Hill. This was then followed by the formation of the School of Military Intelligence (SMI) on 3 March 1969 at the SAF Training Institute. SMI Allowed officers and men to be trained in the field of military intelligence which helped facilitate the build-up of combat units during its early years.
The decade spanning the end of 1970s to the end of the 1980s brought a large restructuring of SMI. In 1978, the Scout Wing and Advanced Intelligence Officer's Wing were established. In 1988, Combat Exercise Wing was established to conduct intelligence training at three levels (Headquarters, Division and Brigade). This took place concurrently with the reorganization of the Advanced Intelligence Officer's Wing and the Specialist Officer's Wing to form the Advanced Intelligence Staff Wing.
The evolution of the Army Intelligence continued into the 2000s with the restructuring of Combat Intelligence Department in G2 Army into Combat Intelligence Group (CIG) on 27 April 2005 and to function as a Ground Specialist HQ to prepare Army Intelligence in dealing with challenges of the Army's new operating environment.
In August 2007, CIG was restructured to form the Combat Intelligence Group/SAF Military Intelligence-Institute (CIG/SMI-I). The new organisation would take on the dual roles of serving as the Subject Matter Expert for Combat Intelligence and the Intelligence Training Institute of the Military Intelligence Organisation.
In July 2013, HQ Army Intelligence was officially inaugurated to be the SSSO to Raise, Train and Sustain 3G Army Intelligence Capabilities. SMI-Inst will continue to be the training authority for the Military Intelligence Organisation to conduct intelligence training. The new Army Intelligence Formation will provide better focus and supervision to build Army Intelligence to support the Army in a broad spectrum of operations.