Cost of Police Misconduct Act of 2021 This bill establishes a framework to collect and publish data on allegations of misconduct by law enforcement officers at the federal, state, and local levels. Specifically, the bill requires federal law enforcement agencies to report data to the Department of Justice (DOJ) about allegations of misconduct by federal law enforcement officers and amounts paid as judgments or settlements with respect to the allegations. State and local law enforcement agencies must report substantially similar data to DOJ to receive a full allocation of funds under the Edward Byrne Memorial Justice Assistance Grant program. The bill directs DOJ to release annual summaries of the data and create and maintain an online database with the reported data. The bill also directs the Government Accountability Office to report on costs and other issues related to law enforcement misconduct.