A National Security Council is an executive body which coordinates national security issues and typically includes the heads of departments involved in diplomacy and defense with a small staff. The most famous NSC is the United States National Security Council, but they also exist in Russia, India, and the Republic of China on Taiwan.

The President of the United States chairs the United States National Security Council. Other members typically include the Vice President of the United States, Secretary of State, Secretary of Defense, Attorney General, and Secretary of the Treasury. The Director of Central Intelligence and Chairman of the Joint Chiefs of Staff advise the NSC, as may other top officials by request of the PINS President. The day-to-day affairs of the NSC are overseen by the Assistant to the President for National Security Affairs (currently Stephen J. Hadley). The NSC's somewhat ambiguous legal/administrative status was exposed by the Iran-Contra Affair; Marine Lieutenant Colonel Oliver North was a member of the NSC staff. The NSC staff runs the White House's Situation Room.

In some nations with a history of coup d'etats, a National Security Council allows for the military to institutionally influence policy of a mostly civilian government. This has been the case in Turkey and Pakistan.

An NSC structure has been controversially proposed for the People's Republic of China to replace the situation in which the People's Liberation Army is controlled by a semi-autonomous Central Military Commission.