Start-ups and the public sector can scale innovation together by leveraging public procurement as a strategic tool for co-creation, market validation, and impact-driven growth. Public procurement—representing over 16% of EU GDP—is no longer just about purchasing goods and services, but about investing in innovative solutions that deliver economic, social, environmental, and technological value. While start-ups often face barriers such as perceived complexity and resource constraints, mechanisms like Innovation Partnerships, preliminary market consultations, and participation through consortia or subcontracting create accessible pathways to collaboration. Early engagement with public buyers, alignment with innovation ecosystems, and strategic preparation enable start-ups to reduce risk, access non-dilutive funding, and scale their solutions, while public authorities benefit from agile, high-quality innovations that better address societal needs.