"The full monty" (or "the full Monty") is a British slang phrase of uncertain origin. It means "everything which is necessary, appropriate or possible; 'the works'". Similar North American phrases include "the whole kit and caboodle", "the whole nine yards", "the whole ball of wax", "the whole enchilada", "the whole shebang", or "[going] the whole hog".

The phrase was first identified in print by lexicographers of the Oxford English Dictionary in the 1980s. Anecdotal evidence exists for earlier usage; the phrase was also used as the name for some fish and chip shops in Manchester during the same period.

Hypothesised origins of the phrase include:

• Field Marshal Montgomery's preference for a large breakfast, even while on campaign.
• A full three-piece suit with waistcoat and a spare pair of trousers from the Leeds-based British tailoring company Montague Burton. When British forces were demobilised after the Second World War, they were issued with a "demob suit". The contract for supplying these suits was partly fulfilled by Montague Burton.
• Gamblers' jargon, meaning the entire kitty or pot, deriving from the card game called monte.