The school cost Winfrey 40 million U.S. dollars of her own money when it was set up in 2007. The sleekly designed campus, sprawling 52 acres in the suburban community of Henley on Klip just south of Johannesburg, encompasses state of the art classrooms and laboratories equipped with flat screen computers, a yoga studio, beauty salon and well-stocked library, and offer the girls who study there a standard of education that would have once been out of their reach.

The academy has achieved a 100 percent pass rate for this graduating year, with several students achieving good enough grades to obtain scholarships to the best US universities.

One elderly woman who arrived to see her granddaughter graduate, said she was very proud of her hard work.

"I am very glad, I am so happy. I feel blessed, you know," said Vyvian, whose grandaughter is soon to begin studying at a U.S. university.

"They look like angels," she added, referring to the white dresses the girls were wearing for the ceremony.

Admission criteria means the family of each student must earn less than 60,000 rand (8,663 U.S. dollars) annually. Pupils are hand-picked for displaying strong leadership qualities in interviews.

Winfrey says the idea for the school was inspired by her own humble beginnings, and that she wanted to give disadvantaged girls the opportunity to have the best start in life.

Tuition and board is free at the residential school.

The South African government has been criticised for neglecting public schools particularly in poor and rural areas where classrooms are often overcrowded and inadequately funded. High levels of classroom violence, teenage pregnancy and drug abuse exacerbate the poor standard of education.

While authorities seek to expand a programme to waive school fees for some of the poorest South Africans, many believe that the legacy of apartheid-era laws remain a disadvantage for underprivileged black students.