生物催化（英语：Biocatalysis）是使用天然催化剂酶，对有机化合物进行的化学转化。这种反应过程又被称为“生物转化”。离体的酶和活细胞中的酶都可以参与到这一活动中。

Biocatalysis (/ˌbaɪoʊkəˈtælᵻsᵻs/) is catalysis in living (biological) systems. In biocatalytic processes, natural catalysts, such as protein enzymes, perform chemical transformations on organic compounds. Both enzymes that have been more or less isolated and enzymes still residing inside living cells are employed for this task.