Co-creation, a powerful and collaborative approach, is not just a method but a catalyst for change. It empowers local leaders, transforms health systems, and addresses power imbalances. This brief describes how the USAID-funded Health Systems Strengthening Accelerator (the Accelerator), led by Results for Development (R4D), utilized co-creation to build effective and sustainable health systems. Engaging multiple stakeholders, including local public and private sector actors, co-creation has proven particularly valuable in designing health systems strengthening solutions that support and promote localization.