This chapter explores the intersection of sustainability and cultural heritage within the fashion industry, specifically focusing on South Asian traditions and practices. It explores how heritage fashion brands continually preserve traditional craftsmanship, which includes handweaving, embroidery, and natural dyeing, among others. This chapter also deals with sustainable materials like organic cotton, hemp, and plant-based dyes, where their role in reducing the reliance on synthetic fabrics is increased. Nowadays, fast fashion is growing to unimaginable levels, and hence, there is a need to advocate stronger practices to improve sustainability and lead to slow fashion. So, in this chapter, we also discuss the importance of slow fashion, which includes and prioritizes timeless designs and high-quality craftsmanship, which causes the shift from the former. There is a culture exchange due to the collaboration between heritage and fashion, which in turn brings the artisans, designers, and collaboration of different diverse cultural regions and backgrounds, promoting mutual understanding and sustainable production techniques. Methods of circular fashion, like upcycling and repurposing, are used by heritage fashion brands, which contributes to waste reduction. The main purpose of this chapter is to explore the role of heritage fashion in preserving cultural heritage and traditional practices from different South Asian regions. Finally, this chapter examines innovative sustainable business concepts within heritage fashion, including circular economy approaches. This chapter presents information on how fashion businesses integrate sustainability and cultural heritage preservation to gain a competitive advantage in the apparel industry, which also makes a positive societal impact.