Brands are adopting green marketing techniques to improve their environmental performance and consumer perceptions in response to the growing demand for sustainable fashion. Consumer expectations in the fashion industry are changing due to growing environmental concerns, which are driving brands to adopt more sustainable and transparent methods. Using brand value and authenticity as mediating variables, this study investigates how green products and green promotion affect environmental sustainability. The study uses Signaling Theory to explain how eco-friendly marketing strategies and sustainable product features serve as credibility signals that influence consumer trust and perceived brand strength. Customers' interactions with sustainable fashion firms were examined using a quantitative method. The results show that green products and green marketing greatly increase brand value and authenticity, both of which have a favorable impact on environmental sustainability. The impact of green marketing strategies on sustainability results is partially transmitted by both mediators. Green products and green promotion greatly improve brand-related perceptions, which in turn improve sustainability outcomes, according to a systematic survey of fashion customers. The findings highlight how crucial real green signals are for promoting ethical consumer behavior and advancing long-term environmental objectives. By highlighting the significance of credible green signals in boosting consumer confidence and encouraging environmentally responsible behavior, the study adds to the body of knowledge on sustainable fashion.