The goal of this research was to analyze the impact of consumer behavior on the sustainability of the fast fashion industry, specifically in regards to the framework of the Triple Bottom Line. First, a review of relevant literature investigating the three aspects of the Triple Bottom Line (environmental, social, and economic) as it pertains to the fast fashion industry was conducted to provide context for this research. Research methods utilized scholarly articles and journals along with companies’ CSR reports to determine the course of development of the fast fashion industry over time. Additionally, the impact of consumer behavior was investigated and linked to trends observed in the production and business practices of the industry over time. Based on the analysis of the influence of past consumer behavior on the industry, it was clear consumers play a major role in the industry and its sustainability in terms of the Triple Bottom Line. This suggests that the unsustainability of the fast fashion industry is due in part to consumer behavior and the retailers themselves, which is important to understand for the industry going forward as it aims to improve overall sustainability.