Moral outrage is one of the most compelling, complex, and powerful emotional responses. It is the affective currency that drives collective action in a democracy, where it can rally constituents, incentivize legislation, affect how we vote, and catalyze individual anger into righteous protests or mob rule. In recent years, outrage has bolstered extremism and political polarization, and it spurred thousands of self-prescribed "patriots" to storm the U.S. capitol. But it also gave birth to new social justice groups such as Black Lives Matter and March for Our Lives, and what began as an outraged tweet ultimately grew into the global #MeToo movement. This book offers the first interdisciplinary study of the myriad ways moral outrage is articulated, invoked, and mediated in contemporary U.S. society, from feminist and indigenous politics, climate activism, and school curriculum debates, to book banning, alt-right rhetoric, literature and entertainment venues. Setting its focus on the social dynamics and cultural effects of collective outrage, these timely essays underscore its vital function as a galvanizing force in identity politics, social change, policymaking and civic engagement.