The Oscar-nominated star of Juno has announced that he is transgender, introducing himself as Elliot Page in a social media post.
The Canadian-born actor said he could not "begin to express how remarkable it feels to finally love who I am enough to pursue my authentic self".
"I love that I am trans. And I love that I am queer," he wrote on Twitter.
Page also used the post to address discrimination towards trans people.
"The truth is, despite feeling profoundly happy right now and knowing how much privilege I carry, I am also scared. I'm scared of the invasiveness, the hate, the 'jokes' and of violence," the 33-year-old wrote.
"To be clear, I am not trying to dampen a moment that is joyous and one that I celebrate, but I want to address the full picture. The statistics are staggering."
Addressing the trans community, Page said he would "do everything I can to change this world for the better".
Page received international acclaim for starring as a pregnant teenager in the 2007 film Juno.
Other major films include Inception and the X-Men series, while the actor has more recently starred in Netflix series The Umbrella Academy.
Page came out as gay in 2014, telling an audience in Las Vegas: "I am tired of hiding and I am tired of lying by omission."
The actor, who is married to choreographer Emma Portner, has been a prominent advocate for LGBT rights.