Billy Porter has revealed that he has been living with HIV for the last 14 years.
The US star and Emmy winner, 51, was diagnosed in 2007 but said he had since "lived with that shame in silence".
Making it public would also have been "another way for people to discriminate against me in an already discriminatory profession", he explained.
But speaking to a Hollywood reporter Billy said: "There's no more stigma - let's be done with that. It's time."
Porter made his name on Broadway, winning a Tony Award for his role in the musical Kinky Boots in 2013.
He won an Emmy in 2019 for playing Pray Tell, an MC on the 1980s New York ballroom scene, in Ryan Murphy's acclaimed TV drama Pose. He earned Golden Globes nominations for best TV drama actor in both 2019 and 2020.
"I was the generation that was supposed to know better, and it happened anyway," he said of contracting HIV.
"The shame of that time compounded with the shame that had already [accumulated] in my life silenced me, and I have lived with that shame in silence for 14 years. HIV-positive, where I come from, growing up in the Pentecostal church with a very religious family, is God's punishment."
He said he told "everybody who needed to know", explaining: "I was trying to have a life and a career, and I wasn't certain I could if the wrong people knew.
"It would just be another way for people to discriminate against me in an already discriminatory profession. So I tried to think about it as little as I could. I tried to block it out."
'Shame is destructive'
He said he was making it public now because "it's time to grow up and move on because shame is destructive - and if not dealt with, it can destroy everything in its path".
He did not even tell his mother until recently, he said. "I was embarrassed. I was ashamed. I was the statistic that everybody said I would be.
"So I'd made a pact with myself that I would let her die before I told her. That's what I was waiting for if I'm being honest. When we moved her into the Actors Fund Nursing Home, I was like, 'She's not going to be here long, and then I'll write my book and come out and she won't have to live with the embarrassment of having an HIV-positive child.'
"That was five years ago. She ain't going anywhere."
'I feel my heart releasing'
He and his sister made a plan to visit her to break the news, but he decided to do so over the phone on the last day of filming Pose, he said.
"Not two minutes into the conversation, she's like, 'What's wrong?' I said, 'Nothing.' She's like, 'Son, please tell me what's wrong.'
"So I ripped the Band-Aid off and I told her. She said, 'You've been carrying this around for 14 years? Don't ever do this again. I'm your mother, I love you no matter what. And I know I didn't understand how to do that early on, but it's been decades now.'
"And it's all true. It's my own shame. Years of trauma makes a human being skittish. But the truth shall set you free. I feel my heart releasing."
Modern treatments mean people can live long and healthy lives with HIV. "This is what HIV-positive looks like now," Porter said.
"I'm going to die from something else before I die from that. My T-cell levels are twice yours because of this medication."