This paper explores Instagram as an external enabler of social media entrepreneurship, adopting a process-oriented approach for examining how and when enabling mechanisms are activated to enhance entrepreneurial outcomes for platform users. While prior literature indicates that social media technologies play an increasingly influential role in shaping entrepreneurial activity, the precise nature of this relationship has received little empirical attention to date. Using semi-structured interview data from 15 case studies of social media entrepreneurs, we find that Instagram embodies many of the enabling mechanisms proposed by the External Enabler (EE) framework, but that the venture triggering role requires modification, and two novel mechanisms merit future consideration: “Market engagement” and “Resource collaboration”. Additionally, mechanisms are observed across all stages of the entrepreneurial process, with some exerting a particularly prominent role in shaping both markets and products/services through the platform. We highlight various implications for entrepreneurship education and platform design. Keywords: External enabler; Social media entrepreneurship; Social media, Instagram