In the upcoming memoir “Always Young and Restless,” Scott, 64 writes that as a 4-year-old she gained a place in the Hollywood Children’s Theater, which was founded and run by an elderly man named Cosmo Morgan, who is long dead.

In order to appear in the weekly showcase, children were required to have private weekly classes at Morgan’s apartment, she says.

The soap star writes that eventually she was forced to sit on his lap and he quickly progressed to molesting her.

Scott told Page Six that even though she was only a child, she instinctively knew it was wrong and that she looked to her grandmother, who was in the room, for help but that she did nothing.

“I remember when I first started to happen I was 4 years old and I hardly knew that this was wrong and she was sitting probably five feet away and I looked at her, my eyes, I’m sure were wild with the questions, ‘Do you see this? Are you going to stop this?’ And she never did,” she told us.

Scott says the abuse went on for years and that she still has not forgiven her grandmother, who died years ago.

“I’m not ready for that then I don’t know if I ever will because when they are aware they become complicit and that to me is evil,” she said forcefully. “You don’t allow that to happen to a small child.”

Scott, who has played fan favorite Nikki Newman since 1979, says that she believes her grandmother was mentally ill, explaining to Page Six, “If it were today and she was diagnosed I’m quite sure it would be borderline personality along with a few other things and she also was overly ambitious and naively believed that whatever we had to do to get further of head in the business  was perfectly fine with her, obviously.”

The memoir comes out on August 18.