Extreme Risk Protection Order and Violence Prevention Act of 2021 This bill establishes a new grant program to help states and Indian tribes implement extreme risk protection order laws. Extreme risk protection order laws, or red flag laws, generally allow certain individuals (e.g., law enforcement officers or family members) to petition a court for a temporary order that prohibits an at-risk individual from purchasing and possessing firearms. The bill also expands the categories of persons who are prohibited from receiving, possessing, shipping, or transporting a firearm or ammunition. Specifically, it adds a new category of prohibited persons: persons who are subject to an extreme risk protection order.