The Ministry of National Defense is the cabinet-level administrative office in charge of "maintaining the independence and sovereignty" of Chile. It is also charged with planning, directing, coordinating, executing, controlling and informing the defense policies formulated by the President of Chile. The minister supervises all the Chilean armed forces. It is Chile's ministry of defence.

The Ministers of State of Chile, according to the Chilean constitution, are the direct and immediate collaborators of the President of the Republic in the government and the administration of the state, and in such, they are responsible for the handling of their respective Ministry (Ministerio), in accordance with the policies and instructions that it imparts. The president can appoint and remove ministers freely, and each reports to directly to the president.