Executive director, National Nurses United
Castillo has headed the largest union and professional association of registered nurses in the United States since 2018. She leads at a time of increasing union activity among nurses and other healthcare workers, with thousands of employees staging strikes in 2022. Castillo has testified before the Senate on the importance of Medicare for All and has spoken out in favor of nurse-to-patient ratio standards. She has worked in organizing for decades, starting with efforts to unionize her facility as a registered nurse.