The alt-right is a growing radical right-wing network that is particularly effective at mobilizing emotion through digital communications. Introducing 'white thymos' as a framework to theorize the role of rage, anger, and indignation in alt-right communications, this study argues that emotive communication connects alt-right users and mobilizes white thymos to the benefit of populist radical right politics. By combining linguistic, computational, and interpretive techniques on data collected from Twitter, this study demonstrates that the alt-right weaponizes white thymos in three ways: visual documentation of white victimization, processes of legitimization of racialized pride, and reinforcement of the rectitude of rage and indignation. The weaponization of white thymos is then shown to be central to the culture of the alt-right and its connectivity with populist radical right politics. KEYWORDS Alt-right; populist radical right; white nationalism; social media; affect; Twitter The recent increase of research into the alt-right has uncovered much of the structure and ideology of this movement. However, how the alt-right captures the attention of its audiences and the forms of affect and emotion that it mobilizes are aspects of this movement that are not well understood. While the 'alt-right is unlike any racist movement we have ever seen. It is atomized, amorphous, predominantly online, and mostly anonymous' (Hawley 2017, p. 3), it is a product of decades of white supremacist organizing in the United States and far right ideology and narratives in Europe and North America. Moreover, the term alt-right is challenging to define, but it can be understood as an umbrella term for a set of radical right social movements active primarily (but not exclusively) in Anglophone countries. It has come to be understood in the literature as a contingent coalition of activists, usually networked online, that span online troll cultures, misogynists in the manosphere, neofascists, ultranationalists, identitarians, and white