The relocation of textile and apparel manufacturing to the Global South has served as a double-edged sword, spurring economic development while simultaneously contributing to environmental degradation, thus creating a potentially irreparable imbalance that threatens the well-being of future generations in the region. This chapter offers a comprehensive exploration of environmental sustainability within the Textile and Apparel Global Value Chain (T&A GVC), with a particular focus on the critical role played by suppliers in the Global South. By leveraging a novel analytical GVC framework enriched with insights from international business (IB) and environmental justice (EJ) literature, this chapter seeks to address significant gaps in current research, especially the underutilization of these theoretical perspectives in the study of sustainability practices. Four key research gaps are identified: the limited integration of IB and GVC theories in sustainability studies, the underappreciated relevance of EJ principles in GVC analyses, the insufficient focus on the governance role of suppliers in the Global South, and the lack of incorporation of planetary boundaries in sustainability assessments. To bridge these gaps, this chapter introduces an innovative analytical GVC framework, with three extensions, that provides a holistic approach to understanding environmental sustainability within the T&A GVC. This framework facilitates a detailed examination of the six dimensions of GVCs—input-output structures, geographic and industrial reach, governance mechanisms, paths for upgrading, industry stakeholders, and institutional dynamics—emphasizing their interconnectedness and the complexity of promoting sustainability across the value chain. By advancing a framework that integrates diverse empirical and conceptual studies, this chapter makes a significant contribution to the literature. It challenges the traditional focus on lead firms and advocates for a more inclusive understanding of sustainability that incorporates the perspectives of suppliers from the Global South. The findings underscore the necessity of adopting a holistic approach to GVCs, one that concurrently considers economic, social, and environmental dimensions to achieve sustainable development. The chapter concludes by offering recommendations for future research and practical strategies for stakeholders, aligning environmental sustainability practices with the United Nations Sustainable Development Goals (UN SDGs).