Environmental, Social, and Governance (ESG) transparency has emerged as a strategic imperative for multinational supply chains, driven by regulatory mandates, consumer expectations, and investor reporting frameworks. Yet, global supply chains are complex, multi-tiered, and geographically fragmented, creating opacity in sustainability reporting. This study examines challenges in implementing ESG transparency, evaluates global frameworks including GRI, CSRD, and ISO 26000, and analyzes how digital tools such as blockchain, IoT, and lifecycle analytics enhance traceability. Using hypothetical comparative datasets from supply chains in India, China, Europe, and Africa, the findings illustrate gaps between reported ESG compliance and actual on-ground practices. The paper proposes a Global ESG Transparency Integration Model to standardize reporting across countries.