Chief executive Tim Cook, who took over from Steve Jobs in 2011, has never publicly denied his sexuality but has decided to come out to the world to "inspire people to insist on their equality", which he claims is "worth the trade-off" with his personal privacy.
Writing in Bloomberg Businessweek, he said: "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.
"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. It's made me more empathetic, which has led to a richer life.
"It's been tough and uncomfortable at times, but it has given me the confidence to be myself, to follow my own path, and 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.
"The world has changed so much since I was a kid. America is moving toward marriage equality, and the public figures who have bravely come out have helped change perceptions and made our culture more tolerant. Still, there are laws on the books in a majority of states that allow employers to fire people based solely on their sexual orientation. There are 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. Countless people, particularly kids, face fear and abuse every day because of their sexual orientation.
"I don't consider myself an activist, but I realize how much I've benefited from the sacrifice of others. 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."