贝币，一种曾在很多地区广泛使用的交换媒介，古代最原始的货币之一。贝币通常是完整贝壳或者人为加工的特定形状。由于贝壳本身是一种装饰品，其最初是作为交换的商品出现的，其作为商品和货币的区别一直是个争论的话题。

在几乎每一块大陆，包括亚洲、非洲、美洲和澳大利亚，都有贝币发现。被最广泛的用作货币的贝壳是货贝（Monetaria moneta），这一物种广泛存在于太平洋和印度洋的暖水区。

中文中，“贝币”除了上述被用作货币的天然海贝之外，还包括仿造贝壳形状制造的其他材质的货币，如陶贝、玉贝、骨贝、铜贝等。

Shell money is a medium of exchange similar to money that was once commonly used in many parts of the world. Shell money usually consisted either of whole sea shells or pieces of them, which were often worked into beads or were otherwise artificially shaped. The use of shells in trade began as direct commodity exchange, the shells having value as body ornamentation. The distinction between beads as commodities and beads as money has been the subject of debate among economic anthropologists.