In recent years, the fashion industry has been increasingly influenced by concerns related to environmental sustainability, particularly the negative impacts associated with fast fashion such as excessive waste generation, resource depletion, and environmental pollution. These issues have encouraged a shift in consumer behavior toward more sustainable alternatives, with thrift shopping emerging as a notable option. Online thrift platforms enable the resale of pre-owned clothing and accessories at affordable prices, contributing to a circular fashion system by extending product usage and reducing textile waste. The growth of digital technologies and social media has further supported the expansion and visibility of such platforms, making thrift shopping more accessible to a wider audience. This study examines Generation Z consumers in Mumbai, a group characterized by strong digital engagement, exposure to social media trends, and increasing environmental awareness. It aims to explore their motivations, purchasing behavior, and preferences regarding online thrift shopping. The influence of affordability, sustainability consciousness, and digital convenience is also considered. Findings indicate that young consumers are increasingly adopting online thrift platforms due to their cost advantages, distinctive fashion choices, and alignment with environmentally responsible consumption values. The research highlights how digital accessibility combined with ecological awareness is shaping modern fashion purchasing patterns. Overall, this study provides insight into the evolving behavior of urban Gen Z consumers and offers implications for businesses operating in the sustainable and second-hand fashion sector.