This systematic literature review investigates circular supply chain (CSC) optimization approaches in the context of sustainable packaging by analyzing ten key studies that reflect current research trends. The review highlights a wide range of optimization models, including mixed-integer linear programming (MILP) for returnable packaging networks, Stackelberg game models for packaging recycling, multi-objective optimization for closed-loop supply chains, and agent-based modeling for recycling logistics. Key application areas include automotive returnable packaging, express delivery packaging recycling, food packaging efficiency assessment, and plastic waste management. The review highlights contributions in integrating circular economy (CE) principles with advanced optimization methods. It also sheds light on policy implications and the role of technology-enabled solutions such as IoT and fuzzy evaluation models. However, critical research gaps remain, including limited dynamic assessment frameworks, insufficient cross-industry methodology transfer, and robust real-world validation. Overall, the findings provide comprehensive insights into existing optimization approaches and outline promising directions for future research on circular packaging systems.