Use of Force Accountability Act of 2021 This bill requires, as a condition of eligibility for funds under the Edward Byrne Memorial Justice Assistance Grant (JAG) program and the Community Oriented Policing Services (COPS) program, a state or Indian tribe to take certain actions with respect to investigating allegations of use of force by law enforcement officers. Specifically, to be eligible for grant funds under the COPS program and JAG program, a state or Indian tribe must have in effect an independent investigation of law enforcement statute and a law or policy requiring the findings of an independent investigation to be referred for review and possible disciplinary action. The term independent investigation of law enforcement statute means a statute requiring an independent investigation in a criminal matter involving allegations of use of force by a law enforcement officer that resulted in death or injury. The bill authorizes the Department of Justice to award grants to help states and Indian tribes implement an independent investigation of law enforcement statute.