The impact of waste policies and measures from National Determined Contributions (NDCs) on the Sustainable Development Goals (SDGs) is unexamined and creates conditions for policy conflict and incoherence. This participatory case study of North Macedonia quantifies synergies and trade-offs. Our results show twelve times more synergies than trade-offs. The most important synergies concern SDG 8: Decent work and economic growth (score: 10) and SDG 3: Good health and well-being (score: 5) since formalizing the recycling sector is expected to create jobs, economic productivity is expected to improve as a result of increased resource efficiency in industry, and declining pollution is expected to increase health through adequate waste management in landfills. On the other hand, the most important trade-off pertains to SDG 1: No poverty (score: −3) because the incomes of informal workers are expected to decrease, affecting financially vulnerable families. In conclusion, despite being the least emitting sector globally, the waste sector is a promising avenue for mitigating climate change because of its synergistic effects with the SDGs. Circular economy policies in line with the 3Rs: reduce, reuse and recycle hold the most potential for synergies in developing countries. This case study generated momentum for policy implementation by highlighting policy synergies and ideas for the next revision of the NDC. Central to this was the process of fostering dialogue and learning among otherwise siloed policy actors.