High Court judge Thokozile Masipa listed several mitigating factors for sentencing him to less than half the minimum 15-year term for murder, including the athlete’s claim he believed he was shooting an intruder.
“The sentence that I impose on the accused… is six years imprisonment,” she said.
Pistorius, 29, hugged his family before being taken out of the court in Pretoria to begin serving his term.
The double-amputee Olympic and Paralympic sprinter was freed from prison last October after serving one year of a five-year term for culpable homicide — the equivalent of manslaughter.
But an appeals court upgraded his conviction to murder in December.
Pistorius will not appeal against the term
Pistorius shot Steenkamp in the early hours of Valentine’s Day in 2013, saying he mistook her for a burglar when he fired four times through the door of his bedroom toilet.
Pistorius will not appeal against his six-year jail term, one of his lawyers said Wednesday.
“We respect the decision of Judge Masipa and will not be lodging an application for leave to appeal, and Oscar will serve the sentence as handed down,” Andrew Fawcett told journalists.
‘Insult to women’
“We are very disappointed… from five years that we fought against, and now it is six, what is that?” Jacqui Mofokeng, spokeswoman of the ruling ANC party’s women’s league, told AFP after the sentencing.
“It’s an insult to the women of South Africa.” Many legal experts had earlier said they expected a term of between 11 and 14 years.
Pistorius, dressed in black tie, white shirt and black jacket, stared straight ahead in court during the televised proceedings, which were attended by his family and relatives of Steenkamp, a former law graduate and model.
At his sentencing hearing last month Pistorius, sobbing heavily, hobbled on his stumps across the courtroom to demonstrate his physical vulnerability.
His lawyers had argued he should not be returned to jail on account of his anxiety disorder and depression.
Pistorius, who pleaded not guilty at his trial in 2014, has always denied killing Steenkamp in a rage, saying he was trying to protect her.
The Supreme Court of Appeal in December ruled he was guilty of murder, irrespective of who he believed was behind the door, when he opened fire with a high-calibre pistol he kept under his bed. -AFP