No Mask Mandates Act of 2021 This bill nullifies existing federal mask mandates and prohibits future actions to require individuals to wear face masks to respond to COVID-19. Specifically, the bill nullifies the executive order issued on January 20, 2021, that requires the use of face masks in federal buildings and on federal lands; and the emergency order issued by the Centers for Disease Control and Prevention on January 29, 2021, that requires the use of face masks on public transportation conveyances and in transportation hubs. In addition, the bill prohibits (1) federal agencies or offices from issuing any future orders that mandate face masks, and (2) the use of previously appropriated federal funds to implement or enforce masking requirements.