"Zoleka departed from this life on Monday, September 25th, in the company of her loved ones," the message posted on her official Instagram account read.
In a statement released on Tuesday, the Nelson Mandela Foundation also expressed their sympathies to the Mandela family for Zoleka Mandela's terrible death.
"We are saddened by the passing of a dear grandchild of Mother Winnie and Madiba, as well as a Foundation friend."
She was called "a tireless activist for Healthcare and justice" by the foundation.
It said, "Her efforts to prevent cancer and her steadfast dedication to dispelling the stigma associated with the illness will continue to inspire us all."
Following the 2010 car crash death of her 13-year-old daughter Zenani, she became involved in road safety initiatives as part of her activism.