Oprah Winfrey is no longer an only child! The talk show host revealed to her stunned audience that she has a half-sister named Patricia.

Turns out Lady O's sis was put up for adoption as a toddler and eventually was adopted at the age of seven.

Until now, Oprah's mom had kept the big news a secret. On today's emotional show, the three women appear together. Now THAT'S an incredible reunion show for her farewell season!

Click through to learn Oprah's birthname ... and it's a bit ironic!