A defence minister (Commonwealth English) or defense minister (American English) is a cabinet portfolio (position) which regulates the armed forces in a sovereign nation. The minister or secretary of defense is usually a very important role in a cabinet. When cabinets first started appearing in the late 18th century, they were often called "Ministers of War" (U.S., "Secretary of War"), who were in charge of the land forces of a nation. Since the end of World War II, the change was made from war to defence, and also often involved putting the defence minister in charge of both land and sea warfare. Another common reform which occurred at the end of World War II was to place the defence minister in a National Security Council or inner cabinet which allows the head of government to coordinate both military and diplomatic activities.

The Defence Ministry in some countries is a very important ministry, sometimes considered more important than the foreign minister (U.S., secretary of state). It is often assumed by the Prime Minister if war is common for that nation (for example, no less than five Prime Ministers of Israel have held the Defence Ministry during their Premiership). In many nations, it is the very strong convention that the defence minister be a civilian to highlight civilian control over the military. In less democratic countries, the minister is often a uniformed army official.

In the United States, the defence minister has been called the Secretary of Defense since 1947, when the once separate War Department and the Department of the Navy were merged (though the Secretary of the Navy exists to this day, it is no longer a Cabinet level position, being subordinate to the Secretary of Defense). In the United States, military orders typically go from the President of the United States through the Secretary.

In the United Kingdom, the Defence Minister is called the Secretary of State for Defence. In many countries, the formal title is Minister for Defence.

The People's Republic of China is very unusual in that the Minister of National Defence (who is usually a senior although not the highest ranking military officer) and the Ministry of National Defence are both very low ranking, relatively powerless groups which to not have command over the People's Liberation Army. Command of the military belongs in the party and state Central Military Commissions, and the MND exists primarily as a liaison and protocol office to communicate with foreign militaries. Essentially, the MND exists only because most other nations have defence ministries and for protocol and liaison purposes, the PRC needs to have an institution corresponding with that of other governments.

Related articles and lists

• Australia: Minister for Defence
• Canada: Minister of National Defence (list)
• Estonia: Ministers of War of Estonia
• France: Minister of Defence
• Germany: Minister of Defence (list)
  • Prussia: Minister of War
• New Zealand: Minister of Defence
• Spain: Minister of Defence
• Switzerland: Member of the Federal Council heading the:
  • "Department of Defence, Civil Protection and Sports" (list)
  • formerly "Federal Military Department" (list)
• United Kingdom: Secretary of State for Defence (with list)
• United States: Secretary of Defense (with list)