The 35-year-old took to Twitter to announce his arrival saying that "I'm officially a clever boy".
Pienaar's return home completes the career path of the South African international who started his career in his homeland with Ajax Cape Town, before moving to Europe with Ajax Amsterdam.
After leaving Ajax, Pienaar added some more very good clubs to his CV, with spells at Borussia Dortmund, Everton and Tottenham.
The Clever Boys are pleased to welcome Steven Pienaar to the family @therealstevenpi #NewSigning #TransferNews pic.twitter.com/eKDwyOtLEa
— Bidvest Wits (@BidvestWits) 5 de julho de 2017
I'm officially a Clever Boy
— Steven Pienaar (@therealstevenpi) 5 de julho de 2017