Military organization (AE) or military organisation (BE) is the structuring of the armed forces of a state so as to offer such military capability as a national defense policy may require. Formal military organization tends to use hierarchical forms.

A military, also known collectively as an armed forces, are a heavily armed, highly organized force primarily intended for warfare. Militaries are typically authorized and maintained by a sovereign state, with their members identifiable by a distinct military uniform. They may consist of one or more military branches such as an army, navy, air force, space force, marines, or coast guard. The main task of a military is usually defined as defence of their state and its interests against external armed threats.