The Full Monty is a British slang phrase of uncertain origin. It is generally used to mean "the whole lot". However, since the 1997 film The Full Monty, which is about male strippers, uses the phrase to refer to removing every item of clothing it has become associated with nudity, and this is the usual meaning in the United States, where the phrase was unknown before the film's release. The U.S. equivalent is "the whole ball of wax".

There are several possible origins of the phrase, but the most likely seems to be a full three-piece suit with waistcoat and a spare pair of trousers (as opposed to a standard two-piece suit) from the Leeds-based British tailors Montague Burton.

Another possible origin is the large breakfasts eaten by Field Marshal Montgomery, although this is now commonly accepted as apocryphal.