Reuters/Lucy Nicholson
"Today marks a victory for equality, perseverance and love," he wrote.
He also quoted the late CEO and co-founder of Apple Steve Jobs about changing the world. Here are his tweets:
Today marks a victory for equality, perseverance and love.
- Tim Cook (@tim_cook) June 26, 2015
"The people who are crazy enough to think they can change the world are the ones who do."
- Tim Cook (@tim_cook) June 26, 2015
Just minutes after he tweeted, both tweets racked up thousands of favorites and retweets each.
Cook publicly came out as gay in an essay for Bloomberg Businessweek this past October.
"While I have never denied my sexuality, I haven't publicly acknowledged it either, until now," he wrote in the essay from about seven months ago. "So let me be clear: I'm proud to be gay, and I consider being gay among the greatest gifts God has given me."