English law is the legal system of England and Wales, and is the basis of common law^{[dead link]} legal systems used in most Commonwealth countries and the United States except Louisiana (as opposed to civil law or pluralist systems in use in other countries). It was exported to Commonwealth countries while the British Empire was established and maintained, and it forms the basis of the jurisprudence of most of those countries. English law prior to the American Revolution is still part of the law of the United States through reception statutes, except in Louisiana, and provides the basis for many American legal traditions and policies, though it has no superseding jurisdiction.

English law in its strictest sense applies within the jurisdiction of England and Wales. Whilst Wales now has a devolved Assembly, any legislation which that Assembly enacts is enacted in particular circumscribed policy areas defined by the Government of Wales Act 2006, other legislation of the Parliament of the United Kingdom, or by orders in council given under the authority of the 2006 Act. Furthermore that legislation is, as with any by-law made by any other body within England and Wales, interpreted by the undivided judiciary of England and Wales.

Common law (also known as case law or precedent) is law developed by judges through decisions of courts and similar tribunals rather than through legislative statutes or executive branch action. A "common law system" is a legal system that gives great precedential weight to common law, on the principle that it is unfair to treat similar facts differently on different occasions. The body of precedent is called "common law" and it binds future decisions. In cases where the parties disagree on what the law is, a common law court looks to past precedential decisions of relevant courts. If a similar dispute has been resolved in the past, the court is bound to follow the reasoning used in the prior decision (this principle is known as stare decisis). If, however, the court finds that the current dispute is fundamentally distinct from all previous cases (called a "matter of first impression"), judges have the authority and duty to make law by creating precedent. Thereafter, the new decision becomes precedent, and will bind future courts.