This chapter explores the foundational principles of the circular economy and its transformative potential in driving sustainable development. It critically examines the shift from the traditional linear “take-make-dispose” model to a regenerative system that prioritizes resource efficiency, waste minimization, and product life extension. Key concepts such as closed-loop systems, eco-design, industrial symbiosis, and the role of innovation in enabling circularity are discussed. The chapter also highlights global policy frameworks and industry practices that support the transition to circular models. By linking environmental control with economic resilience, this chapter lays the foundation for understanding how circular economy principles can foster long-term sustainability across sectors and value chains.