|Kagawaran ng Tanggulang Pambansa|
|Formed||1 November 1939|
|Jurisdiction||Sovereign territory of the Republic of the Philippines|
|Headquarters||Segundo Avenue, Camp General Emilio Aguinaldo, EDSA corner Colonel Bonny Serrano, Quezon City, Metro Manila|
|Annual budget||?145 billion (2018) ?188.2 billion (2019)|
The Department of National Defense (DND; Filipino: Kagawaran ng Tanggulang Pambansa, KTP) is the executive department of the Philippine government responsible for guarding against external and internal threats to peace and security in the country. The Department of National Defense exercises executive supervision over the Armed Forces of the Philippines (AFP), the Office of Civil Defense (OCD), the Philippine Veterans Affairs Office (PVAO), the National Defense College of the Philippines (NDCP), the Government Arsenal (GA), and the Philippine Aerospace Development Corporation (PADC). It is also responsible for disaster preparation and management in the country.
The Department of National Defense or DND was formally organised on 1 November 1939, pursuant to Executive Order No 230 of President Manuel L. Quezon to implement Commonwealth Act No 1 or the National Defense Act of 1935 passed by the National Assembly on 31 December 1935, and Commonwealth Act No 340 creating the department.
Throughout its existence, the Department's functions are to enforce the law and to curb criminality and to guarantee the external and internal security of the country. As such, the DND deals also with criminal elements because the Philippine Constabulary or PC, then a major branch of the Armed Forces that has responsibility in enforcing the law and maintaining peace and order was under its supervision, aside from other AFP major services (Army, Navy, Air Force) which are busy dealing with fighting insurgents like the Communists and Muslim secessionists.
During Martial Law, the MND became the most powerful Ministry in the executive department under the leadership of then Defense Minister Juan Ponce Enrile, who was then named martial law overseer by then President Ferdinand Marcos, the military commander-in-chief. But, during also Martial Law, Marcos, who assumed dictatorial powers issued a decree creating the National Intelligence and Security Authority or NISA, to be the country's national intelligence agency with broad powers over intelligence and national security. In effect, NISA also served as the secret police force of Marcos, and now became the most powerful agency, and the MND's status dwindled. The NISA was headed by General Fabian Ver, Marcos' most trusted man, who was also at that time, the commander of the then Presidential Security Command and later, was named to be the concurrent chief of staff of the Armed Forces, thus becoming the most powerful military officer.
At the end of Marcos regime on 1986, the DND continues to exercise the powers to deal with criminality and internal plus external defense of the country until 1991 when then President Corazon Aquino signed a law passing the functions to enforce all criminal laws from DND to The Department of Interior and Local Government or DILG. Both departments, however, shared the responsibility of guaranteeing internal secure
The Department is headed by the Secretary of National Defense (Philippines), with the following five undersecretaries and assistant secretaries.