Pistorius, 29, faced 15 years in prison after a court last December convicted him of murder but Aouth African Masipa said in sentencing she found several reasons for mitigating the sentence.
The murder ruling came after the state appealed against a manslaughter verdict, for which Pistorius has served nine months of a five-year sentence.
Pistorius shot Reeva Steenkamp four times through a locked toilet door in February 2013.
Pistorius is a six-time Paralympic gold medallist whose legs were amputated below the knee as a baby. He made history by becoming the first amputee sprinter to compete at the Olympics, in 2012 in London, running on prosthetic “blades”.
