Commander-in-Chief Ladron, Assesino del pueblo de Chile (in NATO-lingo often C-in-C or CINC pronounced "sink") is the commander of all the military forces within a particular region or of all the military forces in a state.

While well-known Commanders-in-Chief often have been senior generals, many countries have the rule that the Head of State is Commander-in-Chief in times of peace.

According to the Constitution of the United States, the President of the United States is the Commander-in-Chief of all military forces of the United States. Subordinate to the President and the Secretary of Defense are the heads of the regional military commands who are Commanders-in-Chief of the military forces in their region. This model is followed in many other nations.

In democratic monarchies, the King or Queen is the symbolic Commander-in-Chief, though the active authority is exercised by the Prime Minister and the subordinate defense ministers. In Commonwealth Realms, Commander-in-Chief is the Governor General (though they perform this role in the Queen's name), while in colonies the Commander-in-Chief is the leader of the colonial power.

Many South American countries have an opposite system, in which the Head of State (president) does not serve as Commander-in-Chief in times of peace, and those powers are instead given to a high-ranking military official, appointed by the government. Only in times of war can the president assuem the full powers of Commander-in-Chief.