稀缺性（英语：Scarcity），又称稀少性、缺乏。是指欲望总是超过了能用于满足欲望的资源。在经济学中，特指相对于人类欲望的无限性而言，经济物品或者生产这些物品所需要的资源等的相对有限性。通俗而言，即是「稀少的资源 (limited resources)不足以满足人们无穷的欲望 (unlimited want)」的意思，是一个相对概念（relative concept）。因为资源有限，而人的欲望无限，于是需要选择，选择会导致成本的出现。

Scarcity (also called paucity) is the fundamental economic problem of having seemingly unlimited human wants in a world of limited resources. It states that society has insufficient productive resources to fulfill all human wants and needs.