Closing the Loop examines eight years of the S+T+ARTS Prize and identifies the pathways and conditions through which art-driven and transdisciplinary projects shape the excellence of European research and innovation (R&I). The study demonstrates that S+T+ARTS Prize award-winning projects substantially contribute to the development of EU and national R&I frameworks and offer practical models for implementing responsible research and innovation, transdisciplinarity, and 5-helix collaboration in ways that are culturally grounded, socially responsive, and ecologically aware.