The 31-year-old man was arrested on Wednesday evening, Warrant Officer Kay Makhubela said.
He was expected to appear in the Protea Magistrate’s Court on Friday.
The Star named the woman as Christell Pienaar, 30. She had five children. Her body was discovered on the Silver Oaks School’s overgrown cricket pitch in Eldorado Park, Extension four, by a passerby on Wednesday. She had a stab wound in her upper body. Her pants had been pulled halfway down.
At the time, Makhubela said five men who were last seen with the woman on Tuesday had been taken in for questioning.