As the textile and fashion industry faces increasing scrutiny over its environmental and social impacts, LCA emerges as an essential tool for measuring and mitigating these effects across the entire product lifecycle. This chapter provides a holistic overview of LCA in the textiles and fashion sustainability discourse, outlining the key stages of textile and fashion production, from raw material extraction to manufacturing, distribution, use, and end-of-life management. The unique challenges and opportunities of each phase in the sustainability discourse are examined in detail with particular emphasis on the ecological footprint of textiles and fashion products, concerning the environmental impact categories, including resource depletion, water use, greenhouse gas emissions, and chemical toxicity. Additionally, the chapter addresses the social and economic implications of production practices, such as labour rights and community impacts, underscoring the interconnectedness of textiles and fashion sustainability. Also, the methodologies for conducting LCA, including ISO standards and software tools, along with the relevant case scenarios that illustrate successful applications in the fashion industry, have been discussed. The challenges and limitations of LCA, such as data quality and variability in product types, are critically assessed to highlight areas for improvement. Finally, the chapter concludes by presenting a succinct discussion on the future trends of LCA in the textiles and fashion industry, focusing on innovations in sustainable practices and circular economy models. The chapter will serve as a valuable resource for textile and fashion sustainability education.