The purpose of this study was to identify segments within the social media networks of major professional sport organizations. Relational data were collected from the Twitter accounts of four major professional sport organizations based in Toronto, Canada. Users within these networks were subsequently parsed based upon their Twitter behavior (e.g., likes, retweets, and follows) and their demographic information using an automated cluster analysis. After revealing characteristics of each segment, the findings highlight both sport focused (e.g., hockey, basketball) and non-sport focused (e.g., mothers, music lovers) subgroups which, in some cases, appear in multiple professional sport team networks. The findings provide the antecedents to social media interaction and suggest managers within professional sport organizations consider this in-formation before forging new or enhanced relationship marketing activities as well as cross-promotional campaigns with additional brands.