And her acting is about to enter a new, more mature phase. It's a career, she admits, to which Amelie was "a wonderful passport".
An extraordinary thing about Tautou is that whatever she's wearing, you can't help but focus on her eyes, which really are as black and as hypnotic as on-screen. She has an engaging presence, with a punchy way of speaking English; until I try to move the conversation away from films.
On her work, she's eloquent. She tells me that through playing Chanel, in the 2009 film Coco Before Chanel, "I think I discovered a new register. I could express a character who had authority. I could escape the sweetness I had previously often been asked to express, despite myself. Coco gave me the possibility of playing something in a harsher vein, playing with more rigour".
And if that suggested a turning point in her career, taking the title role in Therese Desqueyroux seals the deal.
The disturbing heroine of Francois Mauriac's 1920s novel is an intelligent woman who, nevertheless, marries according to the logic of her landowning Catholic family rather than her own, learns the error of her ways and turns to arsenic to solve her dilemma.
"Therese came at exactly the right time for me," she says. "I felt I had acquired a certain maturity and gravitas, and I wanted to take on a role that was complex and troubling. What scared me, though, was that I would not be able to show her ugly side, her jealousy, her desire for vengeance."
She needn't have worried. It's a chilling performance, not least because it's so enigmatic; though we can perceive Therese's spirit, and unhappiness, the thought processes involved when she starts to poison her spouse are withheld.
As directed by the late Claude Miller, an occasionally stuffy period piece is enlivened by a mystery and psychological intensity that are almost Hitchcockian.
"Claude sketches intentions rather than showing them," says the actress, "trusting the spectator to pick up the signs. I really loved working in this way. Underplaying is not necessarily more difficult, but it's more radical.
"I think of the revolt inside her, the contradiction of hating this bourgeois life yet having to live it is so powerful that to hold it back she needs a very thick mask. It was a bit like keeping a lid on a volcano."
Tautou was in Cannes a year ago, when Therese Desqueyroux had its premiere; though sadly she was without Miller, one of France's leading directors, who died shortly after completing the film.
"It was obvious during the shoot that he was ill because every morning he had to have radiotherapy," she recalls. "But he never complained, he was very discreet, he kept all his strength until the very end. That was amazing."
She smiles. "I remember once he came on to the set and I said, 'Wow, Claude, you're so elegant, why are you dressed like that?' And he said, 'This morning I had some medical examinations, so I wanted to impress the sickness.'
"I went to see him a few times afterwards. Of course, at some point we learned that he would die, so it was not a shock. But I never thought he wouldn't win."
As it happens, her next film is about illness, but Mood Indigo will be an altogether lighter affair than Therese Desqueyroux. An adaptation of Boris Vian's cult novel Froth on the Daydream, it is directed by Michel Gondry, the prodigiously inventive music video and film director, most notably of Eternal Sunshine of The Spotless Mind. Tautou plays a woman who has a water lily growing inside her lung, Romain Duris the husband determined to save her.
"It's very difficult to describe this story because it's completely surreal," she says gaily. "And it was a crazy experience walking on to the set to make it. We travelled in clouds and in upside-down cars; the decor transformed every day. Michel has such a personal way of telling a story. He's a very special director because he's a photographer, a drawer, he understands animation. He's a genius."
Tautou recently told the French newspaper Le Figaro that "celebrity makes me awkward". Her response to it is to reveal no opinion or feeling that doesn't pertain to her films. She is gracefully evasive on such reasonable topics as the recent furore in France over film stars' wages.
When asked how her parents, a teacher and a social worker, have responded to her success, she is lost for words. This reticence may be one reason Tautou has not pursued Hollywood further.
"I loved working on The Da Vinci Code, but just because I was in one blockbuster doesn't mean I want to do it all the time. I love my job, but I don't like to be in the spotlight to that extent. I prefer to be in the shadows."
But as soon as we're back to cinema, the sun comes out. She jokes of the lack of opportunities for women given Hollywood's focus on superheroes; my suggestion that she would make a good Catwoman leads to uncontrollable laughter. "Ah! Me? I don't think so. Maybe in the comedy version."
Who: Audrey Tautou, the poster girl for French cinema
What: Latest movie Therese Desqueyroux
When: Opens at cinemas on June 27
- The Independent