Restoring Resilient Reefs Act of 2021 This bill addresses the conservation and sustainability of coral reef ecosystems. Among other things, the bill reauthorizes through FY2024 and revises the Coral Reef Conservation Program; directs the National Oceanic and Atmospheric Administration (NOAA) to provide block grants to states to support state coral reef management and restoration; requires NOAA to establish standards for the formation of partnerships among government and community members for the stewardship of coral reefs; provides statutory authority for the U.S. Coral Reef Task Force to lead, coordinate, and strengthen federal government actions to preserve, conserve, and restore coral reef ecosystems; requires the Department of the Interior to provide grants upon the declaration of a coral reef emergency to implement emergency plans; authorizes Interior to provide scientific expertise, technical assistance, and financial assistance for the conservation and restoration of coral reefs; and establishes a National Coral Reef Management Fellowship Program.