群体遗传学（英语：Population genetics）又称族群遗传学或种群遗传学，是研究在演化动力的影响下，等位基因的分布和改变。演化动力包括自然选择、性选择、遗传漂变、突变以及基因流动五种。通俗而言，群体遗传学则是在种群水平上进行研究的遗传学分支。它也研究遗传重组，种群的分类，以及种群的空间结构。同样地，群体遗传学试图解释诸如适应和物种形成现象的理论。

群体遗传学是现代进化综论出现的一个重要成分。该学科的主要创始人是休沃·怀特、约翰·伯顿·桑德森·霍尔丹和罗纳德·费雪，他们还曾经为定量遗传学的相关理论创建基础。

Population genetics is the study of the distribution and change in frequency of alleles within populations, and as such it sits firmly within the field of evolutionary biology. The main processes of evolution are natural selection, genetic drift, gene flow, mutation, and genetic recombination and they form an integral part of the theory that underpins population genetics. Studies in this branch of biology examine such phenomena as adaptation, speciation, population subdivision, and population structure.