Audiences are at the heart of every media event. They provide legitimation, revenue and content and yet, very few studies systematically engage with their roles from a communication perspective. This dissertation strives to fill precisely this gap in knowledge by asking how do social media audiences participate in global events? What factors motivate and shape their participation? What cultural differences emerge in content creation and how can we use the perspectives of global audiences to better understand media events and vice versa? To answer these questions, this dissertation takes a social-constructivist perspective and a multiple-method case study approach rooted in discourse analysis. It explores the ways in which global audiences are imagined and invited to participate in media events. Furthermore, it investigates how and why audiences actually make use of that invitation via an analytical framework I elaborate called architectures of participation (O’Reilly, 2004). This dissertation inverts the predominant top-down scholarly gaze upon media events – a genre of perpetual social importance – to present a much needed bottom-up intervention in media events literature. It also provides a more nuanced understanding of what it means to be a member of ‘the audience’ in a social media age, and further advances Dayan and Katz’ (1992) foundational media events theory. The findings offer new theoretical, methodological, and practical insights, which carry implications for communication and media scholars, as well as practitioners alike.