Pistorius was convicted of culpable homicide, which carries a maximum prison sentence of 15 years in South Africa, but no mandatory minimum.
Judge Thokozile Masipa could have given him a suspended sentence to be served at home under state supervision.
In delivering her sentence, Judge Masipa said that a “noncustodial sentence would send the wrong message to the community,” but that “a long sentence would also not be appropriate either."