化学生物学（英语：Chemical Biology）是哈佛大学的斯图亚特·L·施莱伯等人所提倡，利用分子生物学的手法，搭配有机化学的方式，探讨细胞内核酸或是蛋白质等生物体内分子的功能或是反应。Schreiber等人指出：“化学生物学是对分子生物学的有力补充，化学生物学是采用化学的手段，如运用小分子或人工设计合成的分子作为配体来直接改变生物分子的功能。

在传统的生物学或是遗传学中，通常是利用基因本身的手法，将基因表现后，探讨生物体分子内的交互作用，以及调控机制等解析。而化学生物学则是利用有机化学的方式，进行分子的合成，进而探讨这些分子对于生物内反应本身的作用等。

Chemical biology is a scientific discipline spanning the fields of chemistry, biology, and physics. It involves the application of chemical techniques, tools, and analyses, and often compounds produced through synthetic chemistry, to the study and manipulation of biological systems. Chemical biologists attempt to use chemical principles to modulate systems to either investigate the underlying biology or create new function. Research done by chemical biologists is often closer related to that of cell biology than biochemistry. Biochemists study of the chemistry of biomolecules and regulation of biochemical pathways within cells and tissues, e.g. cAMP or cGMP, while chemical biologists deal with novel chemical compounds applied to biology.