The club had an option to extend for one more season, but chose not to.
Katza (34) will now work in SuperSport United's offices and begins his first day off the field today.
"I am thankful for the opportunity and the privilege I had to be part of the PSL for the last fourteen years," the former Seven Stars and Hellenic defender said.
"God has allowed me to reach the highest level in my career. I will forever be grateful for that and having made a difference in the game.
"But time has come for me to hang up my boots and continue in the next part of my career off the field," continue the man who was capped by South Africa 19 times.
"It's an easy decision to make because football has never been my first priority. Nobody started and nobody ended my career, it's been set out like this by God way in advance.
"But I thank those who gave me an opportunity. I won't miss the game as much as I will miss the relationships with people that have grown over the years.
"What I am going to enjoy the most now is the time with my family. My wife Adelaide and three kids – Chloe, Aiden and Ryan – is one of the most important areas in my life now.
"Also thanks to Kick Off for their part in my career. I am now looking forward to working with the SuperSport brand."