Jay-Z and Mill also partnered with Philadelphia 76ers co-owner Michael Rubin, Kraft Group CEO and New England Patriots owner Robert Kraft and Brooklyn Nets co-owner Clara Wu Tsai, among others, to help form the organization. Author Van Jones is serving as CEO.
Mill has spoken out about criminal justice reform after he was released from prison in April. The rapper believes that the current system in place keeps young black people incarcerated instead of trying to rehabilitate them.
"Creating the REFORM Alliance is one of the most important things I've ever done in my life," Mill said in a statement. "If you thought my case was unfair, there are millions of others dealing with worse situations and caught up in the system without committing crimes."
"With this alliance, we want to change outdated laws, give people hope and reform a system that's stacked against us," he continued.
Jay-Z appeared on Mill's latest album Championships which topped the U.S. album chart after it was released in November.