Differences among people in the actions they take or the opinions they express do not always reflect differences in underlying attitudes, preferences, or motivations. When people differ in the extent to which they are psychologically licensed (i.e., feet able to act without discrediting themselves), they will act differently despite having similar attitudes, preferences, and motivations. Wanting to do something is not sufficient to spur action; one must also feel licensed to do it. We show that feeling licensed can liberate people to express morally problematic attitudes that those who do not feel licensed are inhibited from expressing. We also show that feeling one lacks license can inhibit people from expressing even morally nonproblematic attitudes that those who feel licensed are comfortable expressing. This chapter explores a wide range of social phenomena in which licensing plays a role and identifies a number of variables that grant or revoke psychological license.