Public spheres are sites of communicative interaction that feature citizens turning their attention to collective problems and democratically legitimate solutions. Closely associated with German critical theorist Jürgen Habermas, the idea of public spheres constituted by a range of publics and counterpublics animates a broad array of interdisciplinary scholarship relating to democracy and political theory, argumentation and deliberation, citizenship and civic engagement, media ecologies and the press, and institutions and power relations. Habermas originally theorized the emergence of the bourgeois public sphere as a counterpoint to the aristocratic regimes of early modern Europe, aiming to rescue select democratic practices from an otherwise flawed ideology. Critics of Habermas’s early formulation of the bourgeois public sphere have noted the presence of a multiplicity of public spheres, rather than a single public sphere, the problem of the public/private divide that is definitive of the public sphere, the role of bodies and emotions in addition to language and reason in the formation and operation of publics and counterpublics, the role of media technologies in sustaining and expanding critical publicity, and the difficulties in extracting knowledge claims from the power relations that constitute them. The idea of public spheres has remained resilient despite these criticisms, as any functioning democracy requires a space between the family, the market, and the state to thematize, problematize, and address the challenges of life in groups. Strong public spheres are characterized by hospitality to counterpublics, groups that distinguish themselves from the rational-critical debate of dominant publics through different dispositions, styles, and strategies for steering public attention. Scholarship on public spheres, publics, and counterpublics continues to proliferate, with new directions accounting for the increased prominence of visuality, ecology, digitality, and transnationality in deliberating bodies.