Deep and throaty, it’s the kind where she throws her head back and it seems to come from the pit of her stomach.
She’s been doing a lot more laughing recently, as she learns how to stop caring what people think of her and take on film projects that make her happy.
“You work so hard to establish some kind of credibility as an actor that it’s nice to feel that maybe I’ve established it enough that I can mess with it a bit,” she says frankly as she leans back in her chair in London.
“I don’t have to be so serious and I don’t have to prove everything every single time and maybe I could just do a movie for the fun of it, just for the joy of hopefully making people laugh.”
After shooting to fame in The Princess Diaries in 2001 and then finding huge success in The Devil Wears Prada, Brokeback Mountain, Rachel Getting Married, The Dark Knight Rises and Interstellar, Hathaway is certainly entitled to enjoy herself.
And it looked like nobody was having more of a ball than her in last year’s Ocean’s 8, in which she sends herself up with joyful abandon as vain movie star turned con-artist Daphne Kluger.
Now she’s playing another scammer in The Hustle, a modern retelling of the 1988 film Dirty Rotten Scoundrels, in which she stars opposite Rebel Wilson.
“I’m enjoying playing bad people, it’s true,” she agrees gleefully. “It’s so nice not to be nice.”
It wasn’t actually deliberate for her to play two shysters in a row, but the parts were too fun for her to say no to.
“I signed on to The Hustle before Ocean’s 8. I was really excited about playing this and then Ocean’s 8 came along and I thought, ‘Well I’m not turning that job down’ and I didn’t think I should step off The Hustle because it’s going to be really, really fun so I just thought, ‘Two conwomen!’
“How many thieves did Cary Grant play? Really, I can do this.”
But Hathaway admits she didn’t always have such a freewheeling approach to her choices, and puts this change of heart down to her three-year-old son Jonathan, who she shares with husband Adam Shulman.
“A few years ago I think I would have been too scared, thinking, ‘Am I repeating myself? Will I be put into a box if I do this thing?’
There is just something about having a child that makes you go, ‘I don’t care. I’m going to be happy and I’m going to make choices that make me happy.'
But Hathaway admits that it isn’t always that simple.
“I don’t know if it’s something that you ever feel that you’ve completely found but it comes more easy.
“I know what it feels like now, so when the feeling comes in you go, ‘OK I’m not going to take this for granted, let’s sit here as long as possible.’
“It’s just like anything, things come and they go.”
Now, at the age of 36, with an Oscar for her role as Fantine in Les Miserables under her belt, she has learned how to make choices that work for her.
“I don’t think I necessarily knew how to be happy before. I think a degree of being happy is letting go and I wasn’t really good at that and I just have a different perspective on that now.
“I just think I’m quicker to laugh, easier to flow with things.”
Dressed in a green, double-breasted trouser suit — “I’m trying to bring the outdoors inside” — she seems relaxed and happy in her own skin, taking pleasure from spending time with funny people who share her sense of humour.
Her director in The Hustle is comedian Chris Addison, best known to British audiences as Ollie Reeder in political satire The Thick Of It and as Toby Wright in the show’s spin-off film In The Loop, as well as a regular panellist on Mock The Week.
Addison cut his teeth as a director on another biting comedy about politics penned by Armando Iannucci, Veep, and makes his feature film debut with The Hustle.
At first, he and Hathaway seem like unlikely collaborators from very different worlds but the Hollywood star says she immediately hit it off with the Brit when they first discussed working together on another project.
“Unfortunately, it didn’t work out but then when Chris came up for The Hustle I had already had so many conversations with him and I’m just so happy that he did this because it’s really great to have someone behind the lens who understands where the funny is and who understands what it’s like to be on the other side.”
One aspect of the film that provided a point of contention between the pair is Hathaway’s accent.
At first, she sounds English, then you develop a sneaking suspicion it’s all part of the con.
“Chris really wanted me to be British in this movie and I just said, ‘I don’t think that is the right choice, I don’t think I can pull it off necessarily.’
"Also England is very specific about who does a British accent and how they do it and I’ve never quite done it for you guys.”
She smiles ruefully. She had a particularly bumpy experience with British audiences after she attempted a Yorkshire accent in the big screen adaptation of the book One Day.
“I was thinking how I was going to do it and I eventually thought, ‘OK what if the character isn’t British but she sounds British?’
"So she’s from somewhere else, and she dresses the way she wants to dress and she lives on the side of a cliff and she just decides she’s going to have the poshest, fakest British accent of all time?
"But it’s going to be a good fake accent, so who would she sound like?
"So I decided she would sound like Mary Poppins, Stewie (from Family Guy) and Patsy (Stone from Absolutely Fabulous).”
At least it’s not Yorkshire again, I offer.
She cackles. "Let’s not talk about it.”