Kanya Cekeshe, who was serving an eight-year sentence for trying to set a police van alight in a 2016 #FeesMustFall protest, was released on Christmas Eve.
Cekeshe was among those who benefited from a remission of sentence for certain categories of prisoners announced by President Cyril Ramaphosa on December 16.
The former media studies student at Footprint Academy in Braamfontein had been in prison since December 2017. He was the last Fees Must Fall activist still in jail.
He was released in the early hours of Tuesday morning.
Two days earlier, another beneficiary of the presidential remission, AbaThembu King Buyelekhaya Dalindyebo, was released from the East London correctional centre, where he was serving a 13-year sentence. He was convicted in 2015 for various charges, including kidnapping, assaulting three young men, and evicting tenants from a farm he owned by setting their homes on fire.