Chris Mahlangu was sentenced to life in prison for the murder of Eugene Terre'Blanche on Wednesday.
Terre'Blanche, the former leader of the right-wing AWB, was bludgeoned to death on his farm on the outskirts of Ventersdorp in April 2010.
The sentence was handed down by Judge John Horn at the High Court in Ventersdorp.
Horn said Mahlangu committed a heinous crime and showed flagrant disregard for human life.
The judge said the convicted murderer conjured up an ill-founded defence during the murder trial.
"Mahlangu must be sentenced to a life-long sentence in prison and he must serve 25 years before he is considered for parole."
He also told Mahlangu that allegations that he was sodomised by Terre'Blanche had no doubt brought the AWB leader's family immense pain.
Patrick Ndlovu (18), who was convicted for breaking into Terre'Blanche's house on the day he was killed, was given a suspended sentence.
Horn said Ndlovu, who spent two years in a youth care centre, had shown genuine remorse for his actions.