This chapter explores the identity of the “bro” as a disingenuous scientist citizen who leverages masculinity, clout, and economic success to weigh in on scientific issues such as technology, climate change, human biology, and COVID-19. By analyzing the digital and mediated rhetoric of Elon Musk (the tech bro), Jordan Peterson (the academic bro), and Andrew Tate (the gym bro), I argue that bros appeal to what I call “brothos” to legitimize their expertise regarding a variety of scientific and technical topics. I demonstrate how the three values of the scientist citizen (goodwill, moral virtue, and practical judgment) are corrupted by appeals to traditional masculinity that confer the semblance of credibility while amplifying harmful ideologies and scientific misinformation.