在面向对象编程中，方法（英语：method）指的是类别（所谓的类别方法、静态方法或工厂方法）、或者是对象（所谓的实体方法）两者其中之一的一种子程序。如同进程化编程语言的进程，一个方法通常以一系列的语句所组成，并以之完成一个动作。其可以借由输入一组参数以制订所需的动作，且一部分的方法可能会有输出值（所谓的返回值）。方法的目的是提供一个机制，以访问（对于读和写）对象或类别的私有数据保存区。

A method (or message) in object-oriented programming (OOP) is a procedure associated with an object. An object is made up of data and behavior, which form the interface that an object presents to the outside world. Data is represented as properties of the object and behavior as methods. For example, a Window object would have methods such as open and close, while its state (whether it is opened or closed) would be a property.