Reopen Schools Safely Act This bill requires the Department of Education (ED) to award grants to states and, through them, subgrants to local educational agencies and institutions of higher education to comply with the guidelines, recommendations, and other public health communications issued by the Centers for Disease Control and Prevention and state and local governments to mitigate the hazards of COVID-19 (i.e., coronavirus disease 2019) in schools. Subgrants must be used for certain activities, such as implementing exposure control plans, hiring personnel and purchasing equipment for health screenings, providing students and staff with personal protective equipment, and purchasing sanitation supplies. Unexpended funds must be returned to ED. Additionally, unused supplies and materials that were purchased with grants may not be resold.