The coffin with white flowers laid on top was carried into the chapel at the crematorium in Port Elizabeth by six people.
Sombre-faced mourners arrived for the private memorial and cremation at the chapel in a quiet location bordering a park in the coastal city where Steenkamp grew up.
The 29-year-old law graduate and cover girl was gunned down at the upmarket Pretoria home of the Olympic and Paralympic star on Valentine's Day.
"She was an angel," said Gavin Venter, an ex-jockey who worked with her race horse trainer father.
Venter said there had been no indication that the glamorous model was troubled in her relationship with the double-amputee athlete known as "Blade Runner".
"I asked her father, her father said no, she was very happy with Oscar, there was no problems, but maybe she was just hiding it away," he told journalists.
Venter said he believed Pistorius, who has been accused of premeditated murder, should be denied bail.
"I'm disgusted and he must be dealt with harshly," he said.
"He's a danger to the public. He'll be a danger to witnesses, he must stay in jail, they mustn't release him."
One of Steenkamp's classmates at a local private Catholic school, Bongiwe Gaxambaa, said she would remember her friend's smile, the way she got along with people, and her love and warmth for others.
"It's kind of only sinking in now that I'm actually here, that she's really gone."
"I wouldn't like him to get bail, just for justice to take its course," she said of Pistorius.