Over the past five years, the circular economy (CE) has become ubiquitous, with packaging a key component for true circularity. CE advocates closed resource loops and zero waste, but packaging remains locked in a linear "design-produce-consume-dispose" model due to material properties and usage needs, creating substantial eco-threatening waste. Packaging design is the foundational step for CE transition. This study reviews CE-related packaging design research, synthesizing state-of-the-art design rules, guidelines, and tools. A framework is proposed, covering material selection determinants, conceptual/development-phase design strategies, and validation/assessment tools/indicators. Future research trends are discussed: material selection, recycling-focused guidelines, assessment tools, design education, and policy.