Within a few minutes of meeting the actor Ellen Page near her Los Angeles home, we’re talking about what she enjoys doing around here, which is going surfing with her girlfriend, artist Samantha Thomas. She likes to watch Thomas, the more experienced surfer, examine the waves. Thomas tells her which way to turn, based on movements in the water that Page can’t even see. “Particularly on days where there are onshore winds, so it’s kind of rough, she’ll say, ‘Oh, a wave’s coming at you, it’s a right, go right’ and I’m just like, ‘What are you looking at? You can read the ocean like that?’ It’s really hot,” she adds, the excitement in her gentle voice suggesting that she is quietly, but madly, in love.

There is nothing hugely remarkable about any of this, especially here in California, except that until February 2014 Page would have been unable to have such a conversation with a journalist. The actor who starred in Juno, Hard Candy and Whip It, all films about tough young women who go against the grain, was living a lie. She was pretending to be straight, or at least “lying by omission”, as she puts it, intent on fulfilling her acting ambitions without any adverse attention, even though she had been out of the closet with her loved ones for years. But the double life had started to take its toll on her sanity, so she decided, a month before the event, that she would come out during a speech at a Las Vegas conference for counsellors of young LGBT people. “I’m here today because I am gay,” she revealed, halfway through an eight-minute talk, to a standing ovation that began before she had even finished. It was Valentine’s Day.

Page was only 26, but had been acting professionally since the age of 10; at 20, she was nominated for an Academy Award for best actress for her role as the eponymous pregnant high-school student in Juno. The gulf between her public and private lives had been growing long enough. “I felt, let’s just please be done with this chapter of discomfort and sadness and anxiety, and hurting my relationships, and all those things that come with it,” she says now, sitting in the corner of a restaurant, in a baseball cap, sipping a green tea. “I felt guilty for not being a visible person for the community, and for having the privilege that I had and not using it. I had got to the point where I was telling myself, you know, you should feel guilty about this. I was an active participant in an element of Hollywood that is gross. I would never judge somebody else for not coming out, but for me, personally, it did start to feel like a moral imperative.”

The day after the speech, she flew straight to Montreal to do reshoots for her role as Kitty Pryde in X-Men: Days Of Future Past, and everyone there told her she seemed totally different. “And I was totally different! Just the immediacy of how much better I felt. I felt it in every cell of my body.”

I'm very proud of the movie [Freeheld], and one of the things I'm most proud about is how it's so not de-gayed

Videos of her confessional moment soon hit YouTube, and have now been viewed by more than 5 million people around the world. It seems extraordinary that the sexuality of one young person in a secular democracy can still make headline news, but then Hollywood is an extraordinary place. As Page herself says, “It’ll be amazing, the day when it’s not a thing, when an actress doesn’t feel like she needs to make a speech. That’s obviously the goal.”

When we meet, she has just finished shooting a film called Freeheld, which she both co-starred in and helped produce; it has been her passion project to get the story behind it turned into a movie. She and Julianne Moore play real-life couple Stacie Andree and Laurel Hester who, in 2005, fought to have their relationship officially recognised so that Hester, a New Jersey police detective who was dying of cancer, could leave her pension to Andree. Page plays Andree, the upfront young car mechanic who gets angry with her older lover for keeping their relationship a secret.

The film got a mixed reception on its US release last year. The New York Times review called it “as generic as the bullet points in a gay rights brochure” and declared that “the lives behind this movie deserve better”, laying some of the blame with screenwriter Ron Nyswaner. Nyswaner responded in a speech at a Los Angeles awards ceremony, claiming that the final production was not true to his script, that it had been “de-gayed” to make queer lives look more mainstream: “The gay characters were idealised, their edges were smoothed out, the conflict between them was softened.”

‘I felt guilty for not being a visible person for the community, and for having the privilege that I had and not using it.’ Photograph: Amanda Friedman/The Guardian

Page and I meet the morning after Nyswaner’s speech, and when I bring it up, it is the only time I see her upset. She says Nyswaner has already apologised personally, “but it was a hard day yesterday”. Her speech falters. “Sorry, it clearly affected me. I’m glad he wrote the apology, because… sorry, it was such a shock to me. I mean, I love the movie, I’m very proud of the movie, and one of the things I’m most proud about is how it’s so not de-gayed. Look, it’s hard to make any independent movie, particularly one that stars two women, and this one also happens to be two, you know, gay women. You will never be able to please everybody, but I cannot even begin to speculate why he would have said that.”

Does Page wish more people had seen the film?

“Of course! But the thing about movies now is they can have really, really long lives.” She points out that people can find it later online, and that if it didn’t have “the life in the American theatre that I wish”, that’s not the end of the story.

I have to ask her what it was like being married to Julianne Moore, which, despite the whole terminal cancer thing, must have been pretty great. Page laughs. “She’s the best, yeah, and she’s an extraordinary person, too. She’s obviously one of the best actresses, I think, ever.” She was thrilled when Moore signed up, because they had never met; now, they are close friends. “She’s just a wonderful, utter delight of a human, who just loves her job and works so hard. And has an awesome family.”

Juno, in 2007, was the film that sent Page’s career stellar. Photograph: Twentieth Century Fox

Ellen Page, real name Ellen Philpotts-Page, grew up in Halifax, in the Canadian maritime province of Nova Scotia. Her father was a graphic designer and her mother a French teacher; Page talks about photos of her as a student in France, before motherhood, “in these beautiful clothes and a really short haircut. She’s stunning.” They divorced when Ellen was tiny, so she spent her childhood between their two houses, a fortnight in each, something she says may have given her an aptitude for “being in new spaces all the time”.

The young Page lacked her mother’s talent for French, “but my mom is so passionate about what she does that it made me respect teachers. I was fortunate that I had something ingrained in me, that I had to do well at school.” She became self-sufficient: riding her bike to the woods, jumping in the lake, playing soccer at a high level. She loved Nova Scotia’s remoteness: “You’re just surrounded by so much beauty and stillness.”

But her mother had family in the big city, Toronto, and on one visit they all went to see The Phantom Of The Opera. “I think that was the only show there, ever, and we couldn’t even sit together.” She learned the words to all the songs; she gives me a few lines of The Music Of The Night, giggling. “I asked my mom, ‘What school do I go to to learn to be Christine?’ and she said, ‘You go to university.’ And I was like, ‘You’ll come with me, right?’ She was like, ‘Honey, by that time, I think you won’t want me to.’ I was like, ‘No, don’t say that!’”

Page left home to work as an actor even sooner than that. She joined the drama club at school, where a casting director spotted her and put her in a television movie, Pit Pony, which became a TV series. “It’s just mind-boggling, what I do now. I sometimes think, what if I was sick that day the casting guy came into school?” There followed more Canadian TV and films, and another movie shot in Europe. She grew very independent; she was supposed to be accompanied by chaperones on set, but because her parents both worked full-time, “we’d finagle it so, say, the horse-wrangler’s daughter was my chaperone”.

At 16, she moved to Toronto on her own, then went to Los Angeles to star in Hard Candy, an astonishing film about a paedophile and a teenage girl who turns the tables on him. I tell her it blew my mind. “Yeah, Hard Candy was intense. My dad came with me to do that. But they were always cool with the subject matter, they trusted me. I think back now to the idea of your daughter moving out at 16, when you’re a child actor,” she pauses. “But I was so disciplined. I knew this was what I wanted to do.” In the film, her character tortures the older man, handing him a noose in a potential forced suicide. “I remember getting ready for those scenes, I was 16, and I was almost separate from myself: shocked by it, and curious, and excited. It was a very exhilarating feeling, and very addictive.”

The trailer for Freeheld

But it was Juno, in 2007, that sent her career stellar, with nominations for the Oscars, Golden Globes and Baftas. At the Oscars, the film won best original screenplay. Thankfully, Page, who was 20 at the time, had an industry mentor to look out for her; by then she hadn’t built her own life in Los Angeles. “I basically lived with Catherine Keener when I was going through Juno’s awards season time, which was wonderful but crazy. It’s like a lot, you know? We’d met when we worked on a film together that nobody saw.” (An American Crime, a true story in which Keener’s character tortures the younger Page; the film never made it to the cinemas.) “So she was really protective and kind.”

After a trip away, Page landed back in LA on her 21st birthday. “I got to Catherine’s house and she had a surprise party for me. I came in and she’d put up balloons and stuff. But I didn’t know anybody, so everyone wore name tags.” Which is how she met her close friend, film director Spike Jonze, wearing his name on his shirt. Peaches, the electro pop star, is now a good friend, too; they met, “weirdly, when I was in Amsterdam with her friend Har Mar Superstar, writing a show we sold to HBO that never got made. I’m crazy about Peaches. I’m going to see her do a show tomorrow.”

‘It’s just mind-boggling, what I do now. I sometimes think, what if I was sick that day the casting guy came into school.’ Photograph: Amanda Friedman/The Guardian

But it’s not all famous friends and parties. After shooting Whip It, directed by Drew Barrymore, Page retreated for a month – not to a Caribbean beach, but to an eco-village in Oregon with total strangers, where she studied permaculture and went to sleep and woke up with the sun. “We created giant composts. We’d pee in a bucket with hay in it, then put the pee buckets on the compost.”

Did she ever think, I’m a movie star now: I could just press a button and get out of here?

“No! I loved it. When I left and everyone in the class was holding hands in a circle, I was fully sobbing. One of those kinds of cries where you’re just… I would not have anticipated that’s what my response would have been. I was ugly crying. There was something really special about it, because I’d gone from shooting Juno to Whip It, and then straight there. And all of that was so incredible, but I was clearly desiring something that really felt connected to the earth. And that’s where I met my best friend, Ian Daniel, who’s been my soul twin ever since.” Daniel is a gay man from Indiana, who had driven to Oregon in an old school bus powered by vegetable oil; he describes their friendship as a “love story”, but not a love affair.

I think my gayness was already playing its role in regards to my career

The soul twins now have a job together, presenting Gaycation for Viceland. The series was Page’s idea, and it involves them going to parts of the world where coming out doesn’t win you a standing ovation: Jamaica, Japan, or lunch with a US Republican senator. In a Brazilian favela, they visit a man who prides himself on murdering gay people. “He said things like, ‘If I’m in my car and I see a gay person, I run them over.’ The moment he walked into the room, it felt like a black hole sucking something out of me. I haven’t experienced anything like it. He didn’t know that we were gay.” Did the thought cross her mind that she could kill him, right then? “Yeah, you do stand there thinking, well, what am I doing?” The man left the room before they could say any more. Other encounters have been more aggressive, with people screaming in Page’s face. “And then the cameras turn off and they hit on the lesbian: that happens a lot. They’re like, ‘You don’t know what you’re missing.’ Fuck off!”

They made another film with a young man who “for whatever reason, wanted us to be there when he came out to his mother, which was one of the most intense experiences of my life.” Did his mother not wonder why there was a camera crew in her kitchen? “He told her that his media friends were here, and she was just sort of like, ‘Cool.’ It was weird, and believe me, we had a conversation about it: is this OK? It was really what he wanted. But before his mother got there, he asked me, ‘How did you do it?’ So I shared that with him. But when I’m looking at the edits of the show, if it’s me talking about myself, it makes me cringe a little. The goal is to go and look at the LGBT culture, at the joy and the liberation.”

In recent years, Page has spoken publicly about domestic violence, trans rights, gay suicides, inequality. “And the thing that I would say you get the most hate about, on social media, in my experience, is if you tweet anything about women’s rights or feminism. It blows my mind. But it’s the thought of not being a feminist that actually blows my mind. I feel that, at least now, there seem to be more women who are willing to say, ‘Yes, I’m a feminist.’ It’s shocking to me that that would ever be an issue, to not say that. I really struggle to wrap my head around that.”

With girlfriend, the artist Samantha Thomas. Photograph: Gregory Pace/BEI/Shutterstock

Otherwise, life is pretty peachy. Page recently bought a modernist house in the Hollywood Hills and says that LA really feels like home now. She and her “awesome girlfriend” have a cute dog called Patters, who gets posted a lot on their Instagram feeds. Plus, Justin Trudeau is the new Canadian prime minister. “And it’s exciting, not only that he got elected and that Stephen Harper’s finally gone, but because the Liberals have a majority in parliament.”

I ask if coming out has affected the roles that are offered to her, and she has to take a breath, nod, sigh. “I’d be lying if I said that wasn’t something I feared, and that’s the big reason so many people haven’t come out. For me, being out within my life became far more important than being in any movie.”

Of course, Page wasn’t exactly getting the typical romcom parts anyway. “Totally. I think my gayness was already playing its role in regards to my career. I’m not naive to that element of the business. I hope it changes.”

We discuss the gender pay gap in Hollywood, and an essay that Jennifer Lawrence wrote about it. “The issue is also about how many female writers there are, female directors, even female soundtrack composers,” Page adds. “I just mean, pretty much every facet of this industry. In my circle of friends, it’s something we talk about all the time. And I feel like there’s finally a conversation happening.” •

• Freeheld goes on general release next month.