A denier is a type of French coin created by Charlemagne. The livre (pound, both monetary and unit of weight) was worth 20 sols (sous) and 240 deniers. The British equivalent was the penny, 240 of which (prior to decimalisation) made up one British pound, or 20 shillings. The symbol for both the old denier, and until recently the penny used in Britain, Australia and New Zealand was d.

The name denier is derived from the name of the Roman coin the denarius.

See also denar and dinar.