The improvement of digital technology and human drive to connect and communicate have made social media an ever-present part of social life and, increasingly, organizational life. By reshaping the ways people interact, organize, take collective action, create and learn, social media both challenges our current understanding of individual and organizational phenomena and lends importance to the exploration of how these phenomena occur through digital-mediation. Despite this, few studies have explored the role of social media in processes of organization creation and emergent identity formation. Of research conducted on social media, more generally, Twitter and Facebook have attracted the most attention, with few studies conducted within the context of Instagram, a visually-rich social networking platform with over a billion users. Responding to increasing calls for the study of social media’s implications for organization studies and for more-specific study of the Instagram platform, this dissertation addresses the role that Instagram plays in affording new ways of organizing, the generative nature of user interactions, and responses to social media visual content in collective identity construction. To accomplish these goals, I have elected to organize my dissertation into three papers. An introductory chapter and literature review set the stage for this work, providing both the theoretical framework for this research and justification of its import to organization studies. The first paper employs qualitative content analysis to understand how users of the social networking platform Instagram enact communication affordances in practice and draws on the social and collective concept of entrepreneuring to explain their implications for organization creation. The second paper draws on narrative thematic and visual analysis to examine how user engagement within the visually-rich context of Instagram fosters the development of collective identity, revealing the important roles of resonance and play to this process. The third paper develops the concept of small social data and illustrates its use in the study of organizational phenomena on Instagram. I conclude this dissertation by integrating the main contributions of these papers to theory, highlighting opportunities for future study, and discussing practical implications for organizations in the digital age more-broadly.