The contemporary business landscape is witnessing an ever-increasing concern for environmental sustainability, which has also surfaced in the apparel industry through the introduction of green apparel. Whether the adoption of green apparel is as a result of growing external pressures on firms to adopt green practices or due to deliberate strategies to incorporate sustainable orientation in the making of products, it remains a topical subject—making a comprehensive account of the existing academic literature indispensable. Furthermore, while academic research on green apparel is undoubtedly at an all-time high, the literature is largely disjointed, necessitating a robust synthesis of the exiting literature to illuminate the existing shortcomings and to provide direction to the future research efforts. A systematic literature review (SLR) was conducted to gauge the existing literary work in this field and to identify research gaps. After the critical review of 90 selected studies, four major themes were extracted: consumer apparel purchase, circular economy, consumer awareness, and barriers. After we identified theme-based critical knowledge gaps in the existing literature, we posed corresponding research questions that provide avenues for future research. The study also constructed a framework with significant practical and theoretical implications. Researchers can obtain a comprehensive understanding of the broader contours of this academic field and, with our meticulously tabulated gaps and potential research questions, explore new dimensions and broaden the horizons of this field.