Bob Mumgaard is a prominent American scientist, entrepreneur, and business leader known for his pivotal role in the commercialization of fusion energy. As the co-founder and Chief Executive Officer of Commonwealth Fusion Systems (CFS), Mumgaard has been instrumental in shifting the paradigm of fusion development from theoretical physics to scalable, industrial engineering. Under his leadership, CFS has emerged as a key player in the global pursuit of clean, limitless fusion power. Mumgaard was born and raised in Nebraska, growing up in the suburb of Papillion. His early interest in the intersection of technology, energy, and climate change was shaped by his Midwestern roots and a broader curiosity about how large-scale technological shifts occur. He pursued his undergraduate education at the University of Nebraska, where he earned a Bachelor of Science degree in Mechanical Engineering and a second Bachelor of Science in Engineering Physics. Following his undergraduate studies, Mumgaard moved to Cambridge, Massachusetts, to attend the Massachusetts Institute of Technology (MIT). His graduate work at the MIT Plasma Science and Fusion Center (PSFC) focused on Applied Plasma Physics, specifically involving the Alcator C-Mod tokamak. During his tenure as a PhD student and later as an MIT fellow, Mumgaard specialized in the design of small superconducting tokamaks and the development of diagnostics to measure internal magnetic fields within fusion plasmas. His doctoral research and subsequent work as a postdoctoral fellow—supported by the MIT Innovation Initiative’s Translational Fellows Program—centered on the critical question of how to bridge the "valley of death" between laboratory fusion research and commercially viable energy production. During this period, he became a strong advocate for fostering partnerships between academia and the private sector to accelerate the pace of innovation. In 2018, Mumgaard co-founded Commonwealth Fusion Systems as a spin-out from MIT. The company’s founding vision was built on the premise that, rather than requiring decades of new fundamental science, the path to fusion energy could be significantly shortened by leveraging high-temperature superconducting (HTS) magnet technology and rigorous, engineering-focused iteration. This approach aimed to build smaller, more affordable, and more powerful fusion devices. As CEO, Mumgaard has overseen the rapid growth of CFS. He led the company through several major milestones, most notably the successful design and testing of a record-breaking high-temperature superconducting magnet, which demonstrated that the magnetic fields necessary for commercial fusion were achievable. This breakthrough was widely viewed as a pivotal moment for the fusion industry, proving the technical viability of the company’s "SPARC" reactor design. By 2026, under Mumgaard’s strategic guidance, CFS had expanded to over 1,000 employees and secured over $3 billion in funding from a diverse array of global investors. Beyond his executive role, Mumgaard is a recognized thought leader on energy policy and the role of "tough tech" in addressing climate change. He has played a key role in the founding and growth of the Fusion Industry Association, a trade organization that advocates for the development and deployment of fusion energy. He frequently serves as a spokesperson for the industry, emphasizing that the race for commercial fusion is not just a scientific challenge but an urgent industrial and logistical one. Through his work, Mumgaard has become a central figure in the effort to transition fusion energy from long-horizon scientific research into a tangible, bankable, and scalable component of the global energy grid.