The Department of National Defence , commonly abbreviated as DND, is a Canadian government department responsible for defending Canada's interests and values at home and abroad, as well as contributing to international peace and security. National Defence is the largest department of the Government of Canada in terms of budget as well as staff. The Department is headed by the Deputy Minister of National Defence, who is the Department’s senior civil servant, and reports directly to the Minister of National Defence. The Department of National Defence exists to aide the minister in carrying out his responsibilities, and acts as the civilian support system for the Canadian Forces.

La Department of National Defence ou Département de la Défense nationale est le ministère de la Défense du gouvernement du Canada qui est responsable des Forces canadiennes.