A wallet, or billfold, is a small, flat case used to carry personal items such as cash, credit cards and identification documents, such as a driver's license. Wallets are generally made of leather or fabrics, and they are usually pocket-sized and are foldable.

The word "wallet" has been in use since the first century A.D. to refer to a bag or a knapsack for carrying articles. The word may derive from Proto-Germanic.[1] The ancient Greek word kibisis, used to describe the sack carried by the god Hermes and the sack in which the mythical hero Perseus carried the decapitated head of the monster Medusa, has been typically translated as "wallet".[2][3] Usage of the term "wallet" in its modern meaning of "flat case for carrying paper currency" in American English dates to 1834 but this meaning was one of many in the 19th century and early 20th century.[1]

"Wallet" was originally a term for any sort of satchel, bag, pouch, or pocket that was used to a carry personal effects. In addition to money or currency, they would also be used for carrying dried meat, victuals, "treasures", and "things not to be exposed". It was considered "semi-civilized" in 19th century America to carry one's wallet on one's belt. Ironically, at this time, carrying goods or a wallet in one's pocket was considered uncivilized and uncommon.[4]