在普通法中，法律原则（英语：Legal doctrine），又译法律学说、法律原理、法理原则，是一组不成文的法律规则、框架，常规、惯例。通常是经由法官在法庭中，针对个别案件做出的判决先例，随着经验累积，慢慢形成了这些一般性的法律原理（principle）。当法律案件完成审理及判决之后，法官会创建起一组规则，可以平等适用于类似案例中。当汇集了足够多的判决先例，在法官之间，就会创建起一系列实质上的（de facto）判决标准，可以适用于类似的案件中。

A legal doctrine is a framework, set of rules, procedural steps, or test, often established through precedent in the common law, through which judgments can be determined in a given legal case. A doctrine comes about when a judge makes a ruling where a process is outlined and applied, and allows for it to be equally applied to like cases. When enough judges make use of the process soon enough it becomes established as the de facto method of deciding like situations.