The 22-year-old's recognition highlights his rapid adaptation since joining the Glasgow giants from Major League Soccer outfit Philadelphia Union, with his displays helping Rangers maintain momentum during an impressive run of results.
Makhanya's award also completed a September double for the club, with manager Derek McInnes collecting the Scottish Premiership Manager of the Month accolade.
Rangers enjoyed a perfect September, winning all five of their matches across competitions, including four league victories. Makhanya was particularly impressive during the period, producing a commanding performance in the Old Firm derby victory over arch-rivals Celtic.
The defender has already made 11 appearances for Rangers this season, establishing himself as an important figure as he continues to adjust to the demands of Scottish football.
His growing confidence at club level was also evident during the recent FIFA international break, when he helped Bafana Bafana register three consecutive victories against Guinea, Eritrea and Egypt.
Makhanya credited the support of his teammates and the coaching staff for helping him settle quickly at Ibrox and maintain his progress.
"I am really proud to receive this award, and I'd like to thank my teammates and all the staff for their support," Makhanya told Rangers media.
"They have helped me settle in and feel part of the group, which makes a massive difference when you join a new club. The coaches are helping me improve every day, and my teammates give me huge confidence on the pitch."
The South African international is determined to build on the recognition and continue contributing to Rangers' ambitions this season.
"I'm pleased to contribute to the team's momentum," Makhanya added. "I want to keep working hard, keep improving, and help the team achieve the results we want."
Rangers return to action on Saturday when they host Kilmarnock at Ibrox after a 20-day break, hoping to extend their six-match winning streak across all competitions.
