Pistorius could be sentenced to years in prison, or he could be given a suspended sentence and a fine and receive no jail time for shooting Steenkamp multiple times through a toilet cubicle door in his home.
More than seven months after Pistorius' trial started, Judge Thokozile Masipa will announce what punishment she has decided on after finding him guilty of culpable homicide, which is comparable to manslaughter, but acquitting him of murder.
Prosecutors have demanded at least 10 years in prison for the double-amputee athlete. His defence lawyers have suggested that three years of correctional supervision, with periods of house arrest and community service, would be appropriate.
Judge Masipa last month ruled that Pistorius did not intend to kill Steenkamp, but he acted negligently and with excessive force in the Valentine's Day 2013 killing.
He was also convicted of unlawfully firing a gun in a restaurant weeks before Steenkamp's death. That normally carries a fine for a first offense, but has a maximum of five years in prison.
Masipa has a wide range of options available to her at the climax of the trial because there is no minimum sentence for culpable homicide.
Pistorius' brother and sister, Carl and Aimee, gave interviews to a South African television station on the eve of the sentencing, describing what they said was a difficult and emotional time in the more than a year-and-a-half since their brother killed Steenkamp.
