This paper evaluates how sustainable marketing contributes to the increase of supply chain transparency, specifically through ethical marketing strategies that intervene in consumer trust and brand image. How a company demonstrates a commitment to sustainability is a quintessentially open exercise in visibility, traceability, and disclosure of practice from source to distribution in a supply chain. Sustainable marketing points out these dimensions by using ethical methods of production and environmental responsibility, which would further increase consumer confidence and loyalty. This paper analyzes how businesses use transparency to create differentiation in a competitive market using qualitative analysis of literature and case studies of Patagonia and Unilever. For example, Patagonia used the “Footprint Chronicles” initiative to disclose information on everything to do with its supply chain. At the same time, Unilever infuses transparency through its “Sustainable Living Plan,” which highlights fair sourcing as well as environmental impacts. The findings indicate that transparent supply chains enhance the authenticity of the brand, aside from the fact that innovation and efficiency are spurred by the fact that companies embrace green technologies to keep up with consumer expectations. However, the paper also presents some issues, such as green-washing and the complexity that lies in the management of global supply chains. These issues, therefore, call for a robust data management system as well as close collaboration with stakeholders to achieve true transparency. Generally speaking, the nexus between sustainable marketing and supply chain transparency plays a critical role in promoting consumerism while adhering to ethical standards and sustainable business practices.