意见领袖（opinion leadership）一词源自于保罗·F·拉扎斯菲尔德（Paul Lazarsfeld）及Elihu Katz的「两级传播」理论（two-step flow of communication）。这个理论是用几个不同的模式试着解释，人进行关于想法、决策或是广告产品效果时会有的反应。

意见领袖是指一个对于媒体熟悉、解释媒介消息或是做为一个二次传播的消息者。意见领袖的特色之一是他的意见在接受他的意见团里中受到尊敬及重视。另外一个意见领袖也许在另一个领域则会成为别的意见领袖的追随者。例如一个电脑工程师会是附近邻居在碰上电脑问题时的意见领袖，他对科技及电脑拥有更多的信息及消息来源，同时也具有能了解这些消息意义的能力。

Opinion leadership is leadership by an active media user who interprets the meaning of media messages or content for lower-end media users. Typically the opinion leader is held in high esteem by those who accept his or her opinions. Opinion leadership comes from the theory of two-step flow of communication propounded by Paul Lazarsfeld and Elihu Katz Significant developers of the theory have been Robert K. Merton, C. Wright Mills and Bernard Berelson. This theory is one of several models that try to explain the diffusion of innovations, ideas, or commercial products.