This chapter introduces readers to the green economy and sustainable development. It defines concepts, principles, and frameworks that drive the world toward environmental sustainability. Starting with the definition of the green economy, this chapter will shed light on the reduction of environmental risks, promotion of resource efficiency, and inclusive economic growth. The chapter further elaborates on the origin and development of sustainable development and how these three fundamental pillars-economic, social, and environmental sustainability-are interconnected. It also focuses on international policies and agreements, including the UN SDGs, which can play a significant role in this transition toward sustainable economies. The chapter offers readers a solid grounding in how sustainable development can meet pressing environmental problems and achieve long-term economic resilience and social equity through exploring the challenges and opportunities presented by implementing green economy principles.