趋异演化（英语：Divergent evolution）是指两个或多个生物学特征具有共同演化起源，但在演化历程中逐渐分化的现象，又称适应。可经由观察不同物种的型态或生物分子，如基因或一些生化途径而得知，是演化生物学的研究对象之一。

一个常见的趋异演化例子是脊椎动物的四肢，这些动物中的四肢可能具有共同起源，但却有不同的构造与功能。除了型态之外，也可应用分子生物学来研究这些现象。例如一个基因与蛋白质串行，可能分化成两种以上的同源基因。

与趋异演化相对的概念是趋同演化（convergent evolution），是指两种以上型态或分子具有相同功能或构造，但却源自不同起源。

Divergent evolution is the accumulation of differences between groups which can lead to the formation of new species, usually a result of diffusion of the same species to different and isolated environments which blocks the gene flow among the distinct populations allowing differentiated fixation of characteristics through genetic drift and natural selection. Primarily diffusion, the basis of molecular division, can be seen in some higher-level characters of structure and function that are readily observable in organisms. For example, the vertebrate limb is one example of divergent evolution. The limb in many different species has a common origin, but has diverged somewhat in overall structure and function.