Sport and social media researchers have been challenged to go beyond simply analyzing the content of public social media posts, and to incorporate different critical frameworks to seek more meaningful findings about these relatively new online phenomena. This three-paper format dissertation attempts to frame interactions through sport-themed Twitter hashtags sociologically by incorporating a critical theory rarely deployed in the study of sport—the public sphere. In paper one, the study introduces a theoretical model which suggests sport consumption patterns and the unique architecture of Twitter can promote public sphere-like discourse in hashtags connected to sport. The model suggests amplifiers and barriers which promote or inhibit the creation of an online space for pro-democratic, rational-critical discourse. The second and third papers are empirical tests of the theoretical model—a qualitative case study examination of Twitter hashtag discussions, and they impact they have on participants, following the firing of former Major League pitcher Curt Schilling by ESPN; and a quantitative survey of users of three different types of sport-themed hashtags to assess the generation of social capital as a byproduct of public sphere-like interactions. Together, the three studies comprise the first comprehensive analysis of the public sphere as a way to explain online discussions on Twitter. Given the prevalence of the social media site, and its strong pull among sport fans, better understanding of the motivations for online behaviors—whether reflective of the public sphere or not—can help inform a wide range of issues connected to sport