The talk show host has told the Oprah magazine how she lost a baby when she was just a young teenager.
Oprah revealed she gave birth to a child at the age of fourteen, after years of sexual abuse and promiscuity as a teen.
Friend and editor Gayle King said in the magazine: "She didn't really know who the father was of this child... and hid the pregnancy for a very long time."
The baby, which was born prematurely, died in the hospital shortly after birth.
Gayle added: "It was a secret that she carried for many years because she was very ashamed."
News of the pregnancy was initially leaked by a family member who sold the story to the US tabloid, The National Enquirer, for £8,200.
Oprah confessed: "I took to my bed and cried for three days. I felt devastated. Wounded. Betrayed. How could this person do this to me?
"Only my family and closest friends knew. I would tell no one until I felt safe enough to share my dark past: the years I was sexually abused, from age 10 to 14, my resulting promiscuity as a teenager, and finally, at 14, my becoming pregnant."
But now, Oprah looks at the whole experience as a blessing in disguise:
"I soon realised that having the secret out was liberating... What I learned for sure was that holding the shame was the greatest burden of all."