法律社会学（Sociology of law），亦称法社会学或社会法学，从字面上可以作两种解释，即本体论意义上的“研究法律与社会的关系”以及方法论意义上的“用社会学的方法研究法律”。

法律社会学是社会学与法学的交叉学科，诞生于19世纪的“社会学帝国主义”时期。由于法律本身便是一种重要的社会现象，因此当时主要的社会学家（即“古典社会学家”）都对法律有所研究，如马克斯·韦伯、卡尔·马克思、涂尔干、托克维尔等，此即法律社会学之滥觞。

进入二十世纪，法律社会学研究表现出两种不同的进路，即经验主义与规范主义。前者强调经验研究、实例考察、对法律行为进行预测、以及严格的价值中立；后者则强调规范分析、制度分析以及价值判断。这主要是由于二十世纪的法律社会学研究者部分是社会学家、部分是法学家，给研究带来了不同的思维模式。但这并不表示社会学家一定坚持经验主义或者法学家一定坚持规范主义：以美国为例，威斯康星学派以法律科班出身的为主，但注重经验主义，如哈里·波尔、劳伦斯·弗里德曼等；加州伯克利学派以纯粹的社会学家为主，但注重规范主义，如菲利普·塞尔兹尼克、诺内特等。

The sociology of law (or legal sociology) is often described as a sub-discipline of sociology or an interdisciplinary approach within legal studies. Some see sociology of law as belonging "necessarily" to the field of sociology whilst others tend to consider it a field of research caught up between the disciplines of law and sociology. Still others regard it neither as a sub-discipline of sociology nor as a branch of legal studies but as a field of research on its own right within the broader social science tradition. Accordingly, it may be described without reference to mainstream sociology as "the systematic, theoretically grounded, empirical study of law as a set of social practices or as an aspect or field of social experience",. It has been seen as treating law and justice as fundamental institutions of the basic structure of society mediating "between political and economic interests, between culture and the normative order of society, establishing and maintaining interdependence, and constituting themselves as sources of consensus, coercion and social control".