货币学（拉丁语：numisma，nomisma；源自希腊语：νομίζειν，nomízein，意为「按照法律使用」）是指有关流通货币的研究或收集，所谓流通货币包括硬币、代币、纸币及相关物品；同时古币收藏家（numismatists）一词一般指研究硬币的学者或收藏家。学术上，货币学亦包括对用作抵销债务及商品交易的货币及其他缴纳媒介的广泛研究。

在缺乏具结构性的货币系统下，古人生活于一个以物易物及使用当地可找到具有内在价值的物品的社会。时至今日，于缺乏货币系统的群体中，少部分人仍会以物易物。早期的货币被认为是「古里古怪」（Odd and Curious）的，但于以物易的交易中使用其他商品是不可能的，即使使用的是流通货币（情况就如监狱中的香烟一样）。柯尔克孜族使用马匹作为主要的货币单位，并以羊皮找赎零钱。或许羊皮适合于货币学，但马匹则不适合。多个世纪以来，很多对象被用作货币，如贝壳、贵金属及宝石。

Numismatics is the study or collection of currency, including coins, tokens, paper money, and related objects. While numismatists are often characterized as students or collectors of coins, the discipline also includes the broader study of money and other payment media used to resolve debts and the exchange of goods. Early money used by people is referred to as "Odd and Curious", but the use of other goods in barter exchange is excluded, even where used as a circulating currency (e.g., cigarettes in prison). The Kyrgyz people used horses as the principal currency unit and gave small change in lambskins; the lambskins may be suitable for numismatic study, but the horse is not. Many objects have been used for centuries, such as cowry shells, precious metals, cocoa beans, and gems.