Ellen DeGeneres has opened up for the first time about the abuse she had experienced when she was a teenager, revealing that she was sexually assaulted by her stepfather.

During an upcoming episode of David Letterman's Netflix show “My Next Guest Needs No Introduction,” DeGeneres said that she wanted to tell her story so as to help others, recounting that the abuse started after her mother had breast cancer.

"I'm angry at myself because I was too weak to stand up - I was 15 or 16," DeGeneres said. "I mean, it's a really horrible, horrible story and the only reason I'm actually gonna go into detail about it is because I want other girls to not, you know, ever let someone do that."

"He told me when she was out of town that he'd felt a lump in her breast and needed to feel my breasts because he didn't want to upset her, but he needed to feel mine,” she said speaking about her stepfather.

She said that he tried again several times, until one time when "he tried to break my door down, and I kicked the window out and ran".

DeGeneres told Letterman that several women were "scared to have a voice", saying that now it is the right time to speak up.

"It is just time for us to have a voice. It's time for us to have power," she added.