The penal minimalist approach, as one of the new developments in penal policies, emphasizes reducing the use of prison sentences and replacing them with corrective and preventive measures. This research aims to examine the foundations of the tendency towards penal minimalism in the Penal Reduction Law approved in 2020 and compare it with the American legal system. The research findings show that the tendency towards penal minimalistism is rooted in criminological perspectives such as social disability theories, criminal psychology, restorative and Marxist justice, which emphasize the ineffectiveness of prison in reforming criminals and increasing the cycle of crime. From the perspective of criminal law, the reformability of criminals, reducing economic costs, proportionality of punishment, protection of human rights, and the inefficiency of the prison system are among the foundations of this approach. In the American penal system, especially after the enactment of the Prisoner Recidivism Reduction Act (2018), minimalist policies have been pursued with a focus on reducing prison terms, improving prison conditions, implementing correctional and rehabilitation programs, and reducing socio-economic inequalities in the administration of justice. In comparison to the United States, Iranian penal reforms have mainly focused on reducing custodial sentences and developing leniency institutions. The present study, which was developed using a descriptive-analytical method, shows that penal minimalism can help reduce the prison population, reduce