天然产物（英语：Natural product）是在自然界中由活生物产生的那些通常具有药理学或生物学活性的化学物质，可被用于药学上的药物研发与药物设计；而天然产物化学是运用现代化科学理论与方法研究天然药物中化学成分的一门学科。其研究内容包括各类天然药物的化学成分（主要是生理活性成分或药效成分）的结构特点、物理化学性质、提取分离方法以及主要类型化学成分的结构鉴定与生物合成途径等。

A natural product is a chemical compound or substance produced by a living organism—that is, found in nature. In the broadest sense, natural products include any substance produced by life. Natural products can also be prepared by chemical synthesis (both semisynthesis and total synthesis) and have played a central role in the development of the field of organic chemistry by providing challenging synthetic targets. The term natural product has also been extended for commercial purposes to refer to cosmetics, dietary supplements, and foods produced from natural sources without added artificial ingredients.