A widespread and rapid transition to a low-carbon energy system by 2050 is essential to keep pace with ambitious policy goals and avoid the worst consequences of climate change. Innovation is necessary to lower costs and improve performance of existing technologies and to develop new clean energy options that address challenges in harder-to-decarbonize sectors. To examine means by which the U.S. federal government can rise to this challenge, the National Academies of Sciences, Engineering, and Medicine hosted a virtual workshop series "Enhancing Federal Clean Energy Innovation" on July 27 to August 7, 2020. The workshop featured timely, action-orientated assessments of how to strengthen development and penetration of new clean energy technologies. This publication summarizes the presentations and discussions that occurred over the course of the workshop.