In the process of offering the public apology, the Hollywood superstar also confirmed a long running rumour that he is gay.
Star Trek actor Anthony Rapp claims that he was left "traumatised" when a drunken Kevin Spacey made inappropriate sexual advances to him when he was only a teenage boy.
The younger actor, who also happens to be gay, gave an interview about the scary incident during the weekend.
It has now prompted Kevin Spacey to take to Twitter this morning to offer a public apology and, in the process, candidly discuss his own sexuality for the first time ever.
"I honestly do not remember the encounter, it would have been over 30 years ago. But if I did behave then as he describes, I owe him the sincerest apology for what would have been deeply inappropriate drunken behavior, and I am sorry for the feelings he describes having carried with him all these years," Spacey wrote.
Rapp had originally told about the scary episode with Spacey (without revealing his name) all the way back in 2001.
But he says he was now inspired by all the women bravely coming forward about Harvey Weinstein to tell his own story.
He recounted how Spacey brought him to a nightclub when he was only 14-years-old and afterward invited him, along with others, back to his place.
"My impression when he came in the room was that he was drunk ... He picked me up like a groom picks up the bride over the threshold. But I don’t, like, squirm away initially, because I’m like, ‘What’s going on?’ And then he lays down on top of me," he told BuzzFeed.
Rapp says that Spacey was trying to "seduce" him but he was able to "squirm" out of it and absconded.
Rapp said he was terrified by the experience, which he described as “a frozen moment ... In terms of fight or flight or freeze, I tend to freeze.
“As I opened the door to leave, he was leaning on the front door[frame]. And he was like, ‘Are you sure you wanna go?’ I said, ‘Yes, good night,’ and then I did leave,” Rapp said.
Rapp claims that that he would become distressed every time he spotted Spacey on the big screen because it brought on flashbacks of the night in question. He also said he dreaded the thought of having to ever work with Spacey.
Rapp said he considered taking legal action over the ordeal but was told by legal eagles that he didn't have a proverbial leg to stand on, as it would essentially be his word against another actor's.
"I came forward with my story, standing on the shoulders of the many courageous women and men who have been speaking out, to shine a light and hopefully make a difference, as they have done for me," he said on social media after the interview went viral.
I came forward with my story, standing on the shoulders of the many courageous women and men who have been speaking out 1/3— Anthony Rapp (@albinokid) October 30, 2017
As he offered his apology this morning, Spacey also decided to finally go public about his own sexual orientation.
"“As those closest to me know, in my life I have had relationships with both men and women. I have loved and had romantic encounters with men throughout my life, and I choose now to live as a gay man. I want to deal with this honestly and openly and that starts with examining my own behaviour," he wrote on Twitter.