Janssen was born on November 5, 1965 in Amsterdam, The Netherlands and began modeling at a young age, becoming immediately successful in her native Holland. When work for Chanel brought her to New York City in 1984, she decided to stay. Still young for a model (not yet 25), she quit to study creative writing and literature at Columbia University and enrolled in an acting workshop. Having appeared in an episode of Fox's campy night-time soap "Melrose Place” (Fox, 1992-99), Janssen landed her first significant role as Jeff Goldblum's romantic interest in "Fathers and Sons" (1992). She followed up playing a model by day, crime fighter by night in the aptly-named, but otherwise awful television movie "Model By Day" (Fox, 1994), a role she has said she would rather forget. The multilingual actress co-starred with Scott Bakula in Clive Barker's "Lord of Illusions" (1995) before hitting screens in her breakthrough role as the villainous Russian killer who crushes men to death with her thighs in "GoldenEye.”

After “GoldenEye,” Janssen was careful not to fall into the usual trap of so many other models-turned-actresses and avoided roles that amounted to nothing more than onscreen eye candy. She opted instead to tackle a variety of characters that required her to stretch her acting muscles, not just smile pretty for the camera. One of the only actresses to escape Bond-girl oblivion (few of James Bond's female co-stars have gone on to bigger and better projects), the busy actress appeared in six releases in 1998, announcing that she would rather work with quality directors and actors than star in tent-pole movies. She essayed characters ranging from a bitter alcoholic in "The Gingerbread Man" to a Russian-born owner of a gambling joint in "Rounders" to a tough, blue-collar Bostonian in "Monument Avenue.” Woody Allen cast her as a sophisticated book editor in "Celebrity,” reuniting her with her "Gingerbread Man" costar Kenneth Branagh, while Robert Rodriguez tapped her to be a timid high school teacher in "The Faculty.” Her deft performances prompted critics and co-stars to marvel at her chameleonic versatility and uncanny knack for imitating accents.

Janssen slowed down the following year, appearing only in the forgettable horror flick "The House on Haunted Hill.” She returned with gusto in 2000, earning rave reviews for her performance in the romantic comedy "Love & Sex,” playing a magazine journalist tired of writing fluff pieces who starts a column on love and sex as a means to exorcise her past relationship demons, especially the breakup with her neurotic painter boyfriend (Jon Favreau). Janssen next landed her biggest role to date, playing the conflicted Jean Grey in Bryan Singer’s excellent adaptation of the Marvel comic “X-Men” (2000). She returned to comedy in the Favreau-helmed vehicle, "Made" (2001), again showing great chemistry with Favreau and a effective range in an otherwise small role. In the kidnapping thriller "Don't Say a Word" (2001), Janssen breathed life into the thankless role of Michael Douglas' bedridden wife, imbuing the character with a great sense of vulnerability when their daughter is abducted.

She switched gears in 2002 for the big screen version of the 1960s TV hit "I Spy" starring Owen Wilson and Eddie Murphy—even during the most comedic moments with those two, Janssen demonstrated an ability to keep her performance rooted in reality and, after several turns downplaying her looks, using her considerable sex appeal to great effect. She returned to the role of Jean Grey (with red hair like her comic book counterpart) for the much-anticipated sequel "X2: X-Men United" (2003), setting in motion events that would make her character pivotal to a third outing. Her next move was to the small screen in a recurring role in the 2004 season of FX's hit drama "Nip/Tuck" as the provocative "life coach" Ava Moore whose relationship with the McNamara's teen son revealed a seamier relationship with her own offspring.

After supporting roles in “Eulogy” (2004), a low-budget comedy about three generations of a dysfunctional family gathering in Rhode Island to bury their patriarch, and “Hide & Seek” (2005), a low-budget horror about a widower (Robert De Niro) who discovers his daughter’s imaginary friend is really a malicious and violent reality, Janssen revived Jean Grey for the third installment of the series, “X-Men: The Last Stand” (2006), directed by Brett Ratner. This time, the mutants face a peculiar choice after a cure for mutations is found: retain their uniqueness and remain isolated from society or give up their strange powers and become human.