Mack Williams played football at Dixie Academy and Troy State University. He became the head football coach at his alma mater in 1986 where he remained for thirteen seasons.

Williams led his team to back-to-back State Championships in 1995 and 1996. All but one of his teams during this time made the AISA playoffs.

In 1999, Williams became the head football coach at Lowndes Academy for two years with a 12-11 record before taking over at Pike Liberal Arts for three years with a 12-17 slate . He left Pike following the 2003 season.

Williams was a head football coach for 22 years, including 17 at Dixie Academy. He was the most successful football coach in the programs history with a 116-73-1 record as the Rebels coach.

In addition, Williams was a successful basketball coach, leading Dixie Academy to the AISA Class 1A Finals in 2011. Dixie Academy closed following the 2010-11 school year due to declining enrollment.

Instead of retiring, Coach Williams accepted the head football coaching duties at Ashford Academy prior to the 2011 season where his first two teams made the playoffs. Williams stepped down following the 2014 season at Ashford Academy.