The 27-year-old has signed a four-and-a-half-year contract extension which will keep him at the club until 2024.
Williams has already kept 11 clean sheets from 24 appearances across all competitions so far this season.
SuperSport CEO Stan Matthews said: “In many ways, Ronwen is the poster child of the club. He represents so much of what we stand for in terms of trying to give maximum opportunity for talented young players to shine.
“He joined us as a 12-year-old having to live miles away from his parents in an unfamiliar environment and has worked his socks off to be Bafana Bafana number 1, PSL goalkeeper of the year and an integral part of the last six trophies he has helped us win.”
Ronwen is one of Matsatsantsa’s long-serving players after being with the club for 19 years with 115 clean sheets and 300 club caps under his belt.
— SuperSport United FC (@SuperSportFC) January 17, 2020