The Canadian Association of Defence and Security Industries (CADSI) has its roots in the creation of the Canadian chapter of the American Defense Preparedness Association (ADPA) on November 30, 1983. The organisation's founding mission was to be patriotic, educational, scientific, and non-political. As a non-profit making membership society, it was dedicated to scientific, engineering, industrial, and management preparedness for the common defence of Canada. The organisation believed these attributes to be the strongest guarantees of national security and peace. In 1987, the chapter became an independent association under the name Canadian Defence Preparedness Association (CDPA).
On November 25, 1997, CDPA's Board of Directors voted to change the name of the association to the Canadian Defence Industries Association (CDIA). The organisation operated under this new name until the Association's Annual General Meeting in December, 2005, when the Board of Directors resolved to widen the scope of the organisation's representation and mandate in light of the increasingly integrated nature of the national defence and public security of Canada. At the December 6, 2005 Annual General Meeting, with the will of the members, the Canadian Defence Industries Association changed its name to the Canadian Association of Defence and Security Industries (CADSI).