Comparative law is the study of differences and similarities between the law of different countries. More specifically, it involves study of the different legal systems in existence in the world, including the common law, the civil law, socialist law, Islamic law, Hindu law, and Chinese law. It includes the description and analysis of foreign legal systems, even where no explicit comparison is undertaken. The importance of comparative law has increased enormously in the present age of internationalism, economic globalisation and democratisation.

The birth of modern comparative law is generally attributed to Europe in the eighteenth century. However, prior to that, legal scholars (forerunners of today's comparativists and international lawyers) practiced comparative method. In Russian legal history, for instance, comparative method dates back to the sixteenth century.

According to the prevalent view, Montesquieu is regarded as the 'father' of comparative law. His comparative approach is obvious in the following excerpt from Chapter III of Book I of what many consider to be his masterpiece, De l'esprit des lois:

Richard Frank Hyland (July 26, 1900 – July 16, 1981) was an American rugby union player who competed in the 1924 Summer Olympics.

He was a member of the American rugby union team, which won the gold medal. Hyland also played college football at Stanford University, and went on to become a sportswriter for the Los Angeles Times.

William Twining is the Emeritus Quain Professor of Jurisprudence at University College London. He is a leading member of the Law in Context movement and has contributed especially to jurisprudence, evidence and proof, legal method, legal education, and intellectual history. with recent focussing on "globalisation" and legal theory. Central themes include the variety and complexity of legal phenomena; that many so-called “global” processes and patterns are sub-global, linked to empires, diasporas, alliances and legal traditions; that diffusion, legal pluralism, and surface law are important topics for both analytical and empirical jurisprudence; that, in a world characterised by profound diversity of beliefs and radical poverty, the discipline of law needs to engage with problems of constructing just and workable supra-national institutions and practices; and that adopting a global perspective challenges some of the main working assumptions of Western traditions of academic law.

At the start of his career Twining taught for seven years in Sudan and Tanzania . He has maintained an interest in Eastern Africa, and more broadly the Commonwealth, ever since. He has studied and taught in several leading UK and American law schools.