Zuma appeared in a video that was uploaded on an account called Jacob G Zuma on Friday, December 14 2018.
In it, the former president, wearing a bright floral shirt, said he had decided to "move with the times" and join the national conversation, as he had heard "many people are talking about me".
"Hello everyone," he says.
"I have decided to move with [the] times to join this important area of conversation because I hear that many people are talking about me …
"I’ve felt it is necessary to join in and be part of the conversation and join the people in their discussions.
"It’s me, former president, Jacob Zuma."
"Welcome Baba," said a tweet in response from Julius Malema.
The post got more than 1,000 retweets shortly after it appeared.
TimesLIVE is reaching out to Zuma to confirm whether the account is, in fact, authentic.
Twitter can be a heated environment, with some responding with words of caution.