The Mexican Secretariat of National Defense (SEDENA); Spanish: Secretaría de la Defensa Nacional is the government department responsible for managing Mexico's Army and Air Forces.

[2] Before 1937, the position was called the Secretary of War and Navy (Secretaría de Guerra y Marina).

The agency has its headquarters in Lomas de Sotelo, Miguel Hidalgo, Mexico City.

Alongside his role as a cabinet member the Secretary shares, since 2020, the official ex officio title of "Commanding General of the Mexican Army, Air Force, and National Guard" (Alto Mando del Ejercito, Fuerza Aerea, y Guardia Nacional).

[citation needed] Under the Federal Public Administration Act (Ley Orgánica de la Administración Pública Federal), the Secretary has the following duties, among others provided by the Constitution and relevant laws of Congress: