Apple CEO Tim Cook announced that he identifies as gay in a personal essay for Bloomberg BusinessWeek published Thursday.
"While I have never denied my sexuality, I haven't publicly acknowledged it either, until now. So let me be clear: I'm proud to be gay, and I consider being gay among the greatest gifts God has given me," Cook wrote.
He said that, over the years, he told many people about his sexual orientation. "Plenty of colleagues at Apple know I'm gay, and it doesn't seem to make a difference in the way they treat me," he wrote, adding that he was "lucky" to work at a company that is accepting of him.
Cook has fiercely guarded his privacy even as he runs one of the world's most recognized companies. But, he wrote, he felt that desire for privacy was holding him back "from doing something more important."
"Being gay has given me a deeper understanding of what it means to be in the minority and provided a window into the challenges that people in other minority groups deal with every day," Cook wrote, adding that it gave him the confidence "to rise above adversity and bigotry."
"It's also given me the skin of a rhinoceros, which comes in handy when you're the CEO of Apple," he said.
Human Rights Campaign President Chad Griffin said the announcement "will save countless lives." The group called it a "courageous step forward.
"In doing so, he committed himself to using the influence that comes with heading of one of the world's largest corporations to fight for the rights and equality of lesbian, gay, bisexual and transgender (LGBT) people across America," HRC said.
Cook advocates for LGBT rights, and recently criticized his home state, Alabama, for being "still too slow on equality." He specifically pointed to an Alabama law that allows employers to fire workers based on sexual orientation.
Auburn University, Cook's alma mater in Alabama, said the university community "was proud of Tim as a student, and we're proud of him as a distinguished alum and member of the Auburn family."
Former President Bill Clinton tweeted From one son of the South and sports fanatic to another, my hat's off to you, @Tim_cook."
In the BusinessWeek piece, he mentioned "many places where landlords can evict tenants for being gay, or where we can be barred from visiting sick partners and sharing in their legacies."
"So if hearing that the CEO of Apple is gay can help someone struggling to come to terms with who he or she is, or bring comfort to anyone who feels alone, or inspire people to insist on their equality, then it's worth the trade-off with my own privacy," he wrote.
Hedge fund manager Whitney Tilson called it a "seminal moment when the CEO of the most valuable company on the planet...comes out. And not just by quietly acknowledging it, but with a full-throated roar, saying it's helped him in his career."
Earlier this year, a CNBC anchor mistakenly said on air that Cook was "open" about being gay – a comment that was met with silence by fellow panelists.
An outpouring of support – for Cook and Apple – followed the announcement:
Some backstory to the announcement: Cook reached out to BusinessWeek about writing the piece
"He was very clear on what he wanted," editor Josh Tyrangiel said. "He called and asked if I can come out, and we had a conversation, and he had something written."