Upward social comparison can give rise to the emotion of envy: the pain caused by the good fortune of others. This chapter explains what envy is and what the possible function of envy is to an organism experiencing it. The authors provide an overview of past work on envy, the distinction between two subtypes (benign and malicious envy), possible antecedents of envy, possible consequences of envy, and the responses to being envied by others. In each of these areas, there are clear links to research on social comparison and research on envy has greatly benefited from insights from the social comparison literature. Given the surge in research on envy in the last decade, the authors hope that the findings on envy inspires those investigating social comparisons.