Patricia Clarkson tells me that she’s feeling rather more famous than she used to, which makes sense. A gifted character actress, able to encapsulate patrician poise, suburban angst, bohemian disarray, uptight alpha, and everything in between, Clarkson, 59, has enjoyed a long award-studded career, encompassing film, theatre and television. So extensive is her body of work that it almost amounts to: which Patricia Clarkson do you want? The brittle, drug-addicted lesbian in High Art, the unravelling, gutsy bohemian in Six Feet Under, the cancer-ravaged mother in Pieces of April, the acidic cosmopolitan in The Party? … The list sprawls on. Clarkson has had leading roles, but even when supporting, she tends to stand out.

Her career could be best described as an eclectic blaze, frequently morphing into a fireball – as is happening right now. She has the lead role in her latest film, Out of Blue, an unsettling noir thriller written and directed by Carol Morley (The Falling, The Alcohol Years, Dreams of a Life). Before that, she portrayed the subtly terrifying southern-belle matriarch Adora opposite Amy Adams in HBO’s Sharp Objects, based on the Gillian Flynn novel. As Adora, she encompassed everything from southern primness to neurotic malevolence to deep-set dysfunction. An intricate and compelling performance that, not long after first speaking to me, won Clarkson her first Golden Globe.

Which would seem to explain the extra attention on the street. Though long recognisable in New York (where she lives) and New Orleans (where she was born and grew up, the youngest of five sisters), Clarkson says: “Now it’s gotten a little crazy. I really do have to brush my hair, I really can’t leave my house without a little bit of grooming. And I wear a hat, with glasses – I do, I do, I do! It’s so cheesy, but it really does help.” She rolls her eyes at herself. “But, you know, I’ve worked with people who really do have that burden of fame – George Clooney, Amy Adams. Mega-stars who deal with such craziness every day.”

I put it to her that she’s evolved into a character actress-cum-leading lady – which must be the best of both worlds. “The best,” she agrees. “It’s everything I ever wanted.” And work begets work. “I’ve travelled so many roads in this business, had so many images projected, that I think people can see me now as so many different things, which is exactly where I wanted to be.”

We’re talking at a central London hotel, where Clarkson, svelte and glamorous, but not one for formality, plonks herself down on to a long squashy sofa – in due course kicking off her heels to fold her legs beneath her, beatnik-style. Her onscreen expressiveness continues into real life. She’s quick to laugh, but also thoughtful, creating atmosphere as she speaks – her eyes darting, hands gesturing, her voice lowered to a whisper to emphasise points. She comes across as urbane, with a big sense of humour, and a wild streak. There’s also a thundercrack of old Hollywood charisma – even in person, she has a real sense of drama about her. Part of it is the voice – a distinctive molasses-soaked drawl, which, she tells me, she has in common with her sisters. “People say [that] about my voice and I say: there are five of us, we all have deep voices – it just got deeper and deeper and deeper as it went down the line.”

Out of Blue, also starring James Caan, Jacki Weaver and Toby Jones, is based on Martin Amis’s Night Train, though only loosely. (Morley describes it as “a companion piece to the book”.) The film is ambitiously non-formulaic, the existential end of noir, with Luc Roeg co-producing. (His late father, Nicolas, long planned to film Night Train.) It premiered at the Toronto film festival. The usually blond Clarkson is transformed with dark rock’n’roll hair, playing Mike Hoolihan, a New Orleans homicide detective investigating the death of an astrophysicist (Mamie Gummer), only to find that her own murky childhood origins begin to blur with the case. “I’m always first drawn to the character,” Clarkson says. “Because that’s the journey that I have to take, and that’s the journey that will cause me grief. Then I started to realise the unusual disparate worlds I was in. This very grounded, unadorned, monosyllabic, insular woman, with astrophysics, the cosmos, existentialism and Martin Amis! The film is very different from the book, and that’s also beautiful.”

Going straight from Adora to Mike, Clarkson had to pare down in every sense. “I had to shed all of Adora, I had to take those nails off, hair, eyelashes, dresses, undergarments, and just to be stripped of all of my feminine wiles. And I loved it. It was such a seismic shift as an actress, and as a woman – just to walk in every day and put on those heavy, thick-soled boots. To suddenly have no adornments, no frills, nothing to fuss about… It’s sexier than I imagined playing a masculine type. Though I never thought of Mike as masculine; I think of her as not feminine in the traditional way.”

Facebook Twitter Pinterest Dark and existential: Patricia Clarkson as detective Mike Hoolihan in Out of Blue.

Clarkson is completely pivotal in Out of Blue – there’s barely a moment when she’s not on screen. When I speak to Morley, she says that Clarkson can easily carry a film. “She’s a complete lead. I hope that she gets many more leading roles. I think her not having more leading roles is a fault of the industry and the way it’s evolved. There’s been a lack of imagination with what a female lead should be over the years.” Morley has admired Clarkson’s work for years: “One, I love her voice. That kind of depth of voice. And the way that, with all her characters, she brings such a complexity and depth – that word again – because there is such a depth to her. She can be fairly minimal on the surface, but then you’re really aware of all this stuff going on underneath. Mike needed that, because this is a homicide detective – they’re not going to be overtly emotional, they’re holding it together and generally quite wary. To be able to work within those restrictions is amazing. That was so important for the film. It needed somebody of that stature. She’s just got something very powerful. You can’t take your eyes off her.”

Growing up, Clarkson loved everyone from Ingrid Bergman to Lucille Ball to Peter Sellers. “Though I wasn’t a cinephile as a young girl; I really had a love affair with the theatre.” Her parents still live in New Orleans – her mother, Jackie, was a high-profile local politician and councilwoman, and her father, Arthur, was a school administrator. All the family remain close, which she describes as a “godsend”. As a child, Clarkson would run, kick cans, swim. Later, she was a cheerleader and joined the drama club. I’d been wondering whether it was a textbook southern upbringing – verandas, Tennessee Williams, mint juleps, women like Adora and Blanche Dubois (whom Clarkson has portrayed), but she says her family lived in the suburbs. “Non-gothic, no porches and fans. I was more American dream than southern royalty. But, as a young girl, I did sometimes associate in that world with my grandmother. I did grow up with those ladies. I knew that part of New Orleans. But we really lived a more normal American life, and I think that was good.”

Studying drama at Fordham University in New York City, then Yale, Clarkson learned how to be experimental and daring. “I realised, this is the life I want!” She feels she has continued to push herself. “I’ve taken on some difficult projects. I’ve walked away from some money.” Four years ago, Clarkson portrayed Mrs Kendal in Scott Ellis’s Broadway revival of The Elephant Man, also starring Bradley Cooper, where one scene required her to be naked. Didn’t she feel exposed, for want of a better word? “No, I didn’t. I felt vulnerable, as I should – as the character. It wasn’t easy, by any stretch, but I got lost in it. I never thought of it as ‘the naked moment’… But everyone would remind me of it: ‘Oh, Patti [she narrows her eyes, looking sardonic], we had good seats!’”

Facebook Twitter Pinterest Patricia Clarkson with Bradley Cooper and Alessandro Nivola in The Elephant Man. Photograph: Joan Marcus/AP

Clarkson preferred to steer clear of lengthy television contracts: “Only because I’m claustrophobic – in terms of being tied to one thing for a very long time. It’s difficult to not see an end in sight. That’s why the idea of a five-year contract was anathema to me. I love creating a character, entering that world, and then getting out of it.” She says she would have felt suffocated; stability never interested her. “I have so much stability just as who I am, and family and friends and some of the incredible men I’ve been with in my life – they were all just first-class. It’s because I’ve had those great stabilising forces in my life that I could live on a rollercoaster, I think.”

She is glad that #MeToo is happening, albeit horrified by what people have been through. “God knows I’ve had a million men invite me to a hotel room over the years, but I would never equate what I went through with women whose lives and careers have been ruined – who suffered irreversible trauma and tragedy… My God, the hotel rooms! I couldn’t even begin to tell you the number of times I’ve had awkward moments. I was never put in a deeply compromising position – never. But it was still exhausting and daunting. I was certainly in those ambiguous lanes of: ‘Is he asking me what I think he’s asking me? Does he really want me to go away for the weekend with him? Well, I’m not doing that.’”

When I ask her if she considers herself a feminist, she says she hopes she is: “I think of it as a badge of honour.” She hasn’t married or had children. “I knew from a very young age that I would never marry.” The suffocating thing again? “Just confinement. I’m a free spirit. I live a very unconventional life. And I suffer the slings and arrows of that. In certain situations, it’s: ‘Oh, so you’re not married?’” Has she felt judged? “Absolutely, all the time. It’s: ‘So, have you always been single? Have you ever wanted children?’ Well, maybe once I felt that. But that doesn’t mean I haven’t had beautiful relationships in my life… I’ve had love and heartbreak and all the things except a marriage licence. And I still want love in my life. Of course I do. Who wouldn’t?” Along the way, have people tried to warn you about your choices, even scare you? “Of course, that I was going to wake up at 45 and be in despair… I woke up at 45, and it was,” she claps her hands and kicks a leg in the air, “OK, where are we going tonight?

Facebook Twitter Pinterest Golden Globe winner: Patricia Clarkson as Adora in Sharp Objects. Photograph: HBO

“They don’t know where to put women who’ve defied convention. It’s a little better now, but still shocking. People judge you in a way that’s sexist and ageist. The most sexist that people have been to me is not in this business, it’s me being unmarried. It’s subliminal and subtle. It’s: ‘You live alone?’ ‘Ye-ees.’ And ‘You paid for this apartment?’ ‘No! My fairy godmother showed up in a fucking pumpkin and paid for this apartment!’” We both laugh. “I’ve had my dark nights,” she says, softly now. “Am I envious sometimes of people who have beautiful, long marriages, a kindred spirit, a soulmate, beautiful children to buoy their life? But I have so much family in my life, many great friends, I have a huge life. I don’t need the bedrock. It’s just who I am. I can become a character, but I can’t become a person other than I am.”

When I ask what impact President Trump has had on the US arts community, Clarkson says: “We’re awakened. We’re ‘woke’, as they say. I think we’re over the shock and we’re rallying, moving forward.” Her advice for young female actors is not to allow their image to dominate, on social media or anywhere else. “Enough! We’re already in a self-aggrandising world that puts our looks and glamour at the centre. We need breath and distance from that. As much as we can get.” Clarkson enjoys red-carpet events. “I’m a girly girl! I love getting all dressed up. But that has everything to do with the image and business side of the industry; it has nothing to do with creating a character and playing a part.” She says she even feels uncomfortable – “egomanic, unhealthy” – watching herself on screen with a crowd. “It’s like this obsession with ourselves. It’s not gender specific, it’s men and women both, just losing themselves. But if we’ve so lost ourselves to vanity, how do we ever come back to a real character? I think that’s all tied into us altering our faces and our bodies.” Would she have considered doing that? “I wouldn’t. I don’t condemn or condone. It’s everyone’s own choice. But to an extreme or excess, we can never recover, because we’ve lost the very thing that people are hiring us for.”

Facebook Twitter Pinterest ‘We’re rallying, moving forward’: Patricia Clarkson. Photograph: Suki Dhanda/The Observer

As the interview draws to a close, Clarkson says that what Hollywood needs is more female… well, everything: “Female leads, female directors, female-led, female-driven, multiple stories about multiple females, not just one female at the centre.” She’s enthused by the changes she can see happening in Hollywood. “Women are moving into the space we were always meant to occupy, where we’re meant to be. A major shift is taking place. And I’m riding that shift.”

The next time I speak with Clarkson, she’s back in New York, after winning her Golden Globe. At the press conference afterwards, resplendent in a red Georges Chakra gown, she swished into view, holding her award, saying drolly: “This is what 59 looks like.” In her acceptance speech she gave a nod to #MeToo, thanking Sharp Objects director Jean-Marc Vallée, saying: “You demanded everything of me except sex, which is exactly how it should be in our industry.” Over the phone, she hoots at her on-stage remarks: “That was true! It’s funny, but it’s the absolute truth.” She says she loved winning, seeing the award as belonging to everyone who worked on Sharp Objects. “It’s a swinging night and it’s lovely to win, so you can thank all the people you love and appreciate. I’m thankfully not jaded enough not to be appreciative and grateful.”

By the time you read this, Clarkson will have been queen of the New Orleans Mardi Gras, heading a 50-float parade through the city. “I’m queen of the parade, the honorary muse – Cinderella time!” She’s got a lot of work coming up, which she can’t talk about right now. “The floodgates have opened slightly. The dam hasn’t broken, but I’ve bought new luggage in anticipation. I’m not kidding!” For now, Clarkson is looking forward to the release of Out of Blue. “It’s such an unusual film. There’s nothing like it. I think it will stir people.” She continues to be optimistic about Hollywood, and women generally, but specifically older women. “Things were dramatically shifting even before #MeToo. Now it’s in high gear. It’s cool, it’s proper, to have women, particularly older women, in your projects. Women who lead projects, who win awards, who do well. I’m so excited about the future of our industry – more excited than I’ve ever been.”

Out of Blue is in cinemas from 29 March