Effective and Humane Treatment of Youth Act of 2021 or Kalief's Law This bill establishes requirements for the treatment of youth in the criminal justice system at the federal, state, and local levels. A youth is an individual who is 21 years of age or younger. At the federal level, the bill requires federal law enforcement officers to record youth custodial interrogations, limits the use of solitary confinement for youth at federal facilities, and limits the use of restraints on youth during federal court proceedings. At the state and local levels, the bill places conditions on existing grants and establishes a new grant to incentivize the implementation of similar policies with respect to youth. First, the bill reauthorizes the Juvenile Accountability Block Grant program for FY2021-FY2025. To be eligible for grant funds, state and local governments must implement policies that, with respect to youth, provide a right to speedy trial, provide a right to timely bail consideration, and restrict the use of solitary confinement. Second, a state or local government that receives funding under the Edward Byrne Memorial Justice Assistance Grant program or the Community Oriented Policing Services program must implement policies and training on police-youth interaction. Third, the bill directs the Department of Justice to award grants to help state and local governments record youth custodial interrogations.