Williams, 78, was a long-time local business leader and minority owner of the Dallas Mavericks.
Sonny and his wife, Gretchen Minyard Williams, played pivotal roles in the community and their work with the Mavs Foundation touched countless lives over the years.
“Sonny has been a backbone for the foundation and all of the Mavs philanthropic efforts,” Dallas Mavericks governor Mark Cuban said. “He was always there to help those in need. He was an incredible role model for all of us that is missed dearly. He also had an amazing knack for what fans wanted and always showed his love for the Mavs at every game.