This chapter presents a guiding framework for circular economy implementation in supply chains. Closing the loop for resource efficiency is a well-known practice in the industry. To concretize the circular economy implementation strategies, closed-loop thinking requires innovation and adaptation. Circular supply chains (CSCs) are one of the key enablers in closing the loop by design or intention for value recovery and profit maximization. CSC is an emerging area, and the view of CSC where forward and reverse supply chain is seamlessly integrated with the overall aim to achieve system-wide circularity is missing in the academic debate. By offering a cross-functional and systemic perspective of circular supply chains, we present a guiding framework to structure and understand the underlying complexities and highlight the crucial elements of circular supply chain implementation. The framework categorizes the circular supply chain into four building blocks: systemic approach, main drivers, levels of decision making, and mechanisms to manage the full loop closure and minimize the inherent uncertainties of a complex system. We conclude the chapter by illustrating the applicability of the circular supply chain framework using two industrial cases that are transitioning toward the circular economy.