The Military history of Britain, including the military history of the United Kingdom and the military history of the island of Great Britain, is discussed in the following articles:

• Military history of England: the military history of the nations and tribes that inhabited or occupied the lands that make up England and Wales, before the creation of the United Kingdom under the Act of Union in 1707.
• Military history of Ireland: for the military history of Ireland as a part of the United Kingdom, including the present-day Northern Ireland.
• Military history of Scotland: for the military history of Scotland since prehistoric times to today.
• Military history of the United Kingdom: since its formation in 1707.