Montgomery's 3-person ownership group is comprised of 2 big wigs from the Northland real estate firm -- chairman Larry Gottesdiener and President and COO Suzanne Abair.
"My dream has come true," Montgomery said in a statement to TMZ Sports.
"Breaking barriers for minorities and women by being the first former WNBA player to have both a stake in ownership and a leadership role with the ownership team is an opportunity that I take very seriously. I invite you to join me as the Dream builds momentum in Atlanta!"
Montgomery played 2 seasons with the Atlanta Dream before opting out of the 2020 WNBA season to focus on social justice initiatives.