Oprah's secret: She has a long lost sister.

In promos for the show Oprah said she will reveal a family secret that "literally shook her to her core."

"I was keeping a family secret for months and on Monday you're going to hear it straight from me. I thought I'd seen it all... but this, my friends, is the miracle of all miracles."

After a huge build up, Oprah Winfrey today revealed on her show that she has a half sister that she never knew about. Oprah's sister, Patricia, was put up for adoption at an early age and bounced around foster care until being adopted at age seven. Oprah says her mother never told her she had a sister. Oprah is nine years older than Patricia and they do not share same father.