Green considers herself nerdy: "When people first meet me, they find me very cold. I keep myself at a distance, and I think that's why I'm so drawn to [acting]. It allows me to wear a mask." She moved to Primrose Hill, London in mid-2005, She prefers the "village-like" atmosphere of the London neighbourhood: "I feel more centred when I'm [there]." She lives alone, jokingly referring to her border terrier, Griffin, as her "husband". She is currently dating New Zealand actor Marton Csokas, whom she met on the set of Kingdom of Heaven. She has no particular fitness regime, as, "I'm French and I'm lazy, which means I smoke and I don't exercise", though she does run and practises pilates. Green finds dieting too stressful. She thinks of herself as an international actress: she can speak both her native French and English fluently, and is also learning Japanese as well as perfecting an American accent.

Green's favourite film is Cries and Whispers, and she is a fan of directors Fran