Developing a robust national AI infrastructure will be critical for keeping pace with the rapid advance of AI technologies, accelerating scientific discovery, supporting commercialization, and sustaining U.S. leadership in AI innovation. In June 2025, the National Academies' Government-University-Industry-Philanthropy Research Roundtable held a workshop on how AI infrastructure can catalyze U.S. scientific innovation. The workshop brought together experts from government, academia, industry, and philanthropic organizations to explore the infrastructure needed to support the development and widespread commercialization of AI technologies. The workshop also examined opportunities for strengthening testbeds, data-sharing frameworks, collaboration networks, policies, and cross-sector partnerships, as well as strategies for accelerating the deployment of AI in critical sectors such as healthcare, manufacturing, and national security.