Born on 12 December 1970 in the Catskill Mountains, located in southeastern New York, to Ilene (Schuman), an antique dealer and Gerard Connelly, a clothing manufacturer, Jennifer Lynn Connelly primarily grew up in Brooklyn Heights, near the Brooklyn Bridge and attended St. Ann's, a private school for arts. After graduating from high school, she went to Yale University in New Haven, Connecticut to study English literature and after two years transferred to Stanford University to study drama. However, to pursue her career in films, she left the college in the same year.

Jennifer had her natural talent for modelling since her early days and when she was ten, a close friend of the family, an advertising executive, suggested that her parents take her to a modelling audition. As suggested, her parents sent a picture of her to the Ford Modelling Agency and within a short time, she began appearing in newspaper and magazine advertisements even appeared on the covers of several issues of the American teenage magazine like Seventeen, followed by television commercials. As luck would have it, a casting director spotted her in a commercial and immediately introduced her to the famous Italian film director Sergio Leone, who was in search of a young girl to perform a ballet routine in his Jewish gangster epic Once Upon a Time (1984).

Although Jenifer had no ballet training, she tried to imitate a ballerina and her performance in the audition, along with her resemblance to the adult version of her character, convinced the director to cast her. Despite she had little screen time in the film, her short presence on the screen was enough to reveal her talent.

The next year, another Italian film director, Dario Argento, signed Jenifer to play her first starring role in his thriller Phenomena (1985), in which she played the role of a girl with an amazing ability to communicate with insects and uses her unusual capability to pursue the killer of students of the Swiss school in which she is enrolled.

However, on an unfortunate occasion during filming, she was suddenly attacked by the movie's chimpanzee and eventually had one of her fingers partially bitten off. However, although the film was heavily cut for American distribution, it made a lot of money in Europe. In her next film, Jenifer also appeared in the lead role in the coming-of-age movie Seven Minutes in Heaven (1986). But she achieved public recognition in the fantasy film, Labyrinth (1986), playing the role of Sarah Williams, a teenager on a quest to rescue her brother Toby from the world of goblins. Although the film flopped at the box office, eventually it was considered a modern cult classic.

The teenaged Jenifer Connelly portrayed a college student Gabby in Michael Hoffman’s Some Girls (1988) and also worked in the Italian film Etoile (Ballet 1989), portraying a ballet student of a prestigious ballet school in Hungary where she unknowingly became involved and obsessed with Tchaikovsky's Swan Lake, which eventually changed her personality completely. Impressed by her performance in Some Girls, American film director Dennis Hopper cast Jennifer as Gloria Harper, an ingénue small-town woman being blackmailed in The Hot Spot (1990). Not yet 20, Connelly neatly managed her transition from child actress to an innocent young woman in the film to enact her first on-screen nudity.

Although the film received mixed critical reviews, it was a box office failure but Connelly was praised for her performance in it.

After that, apart from the romantic comedy Career Opportunities (1991), which allegedly exploited her body, Jenifer appeared in the big-budget Disney film The Rocketeer (1991), which proved to be a costly failure for a studio, but a favourite among her devoted fans. During the decade she also appeared opposite Antonio Banderas in a 1994 Argentine-American drama film Of Love and Shadows (1994), played the role of a lesbian college student in Higher Learning (1995), followed by the neo-noir crime thriller Mulholland Falls (1996). Her next appearance was in the critically acclaimed neo-noir science fiction film Dark City (1998), directed by Alex Proyas, in which she portrayed femme fatale Emma, whose husband suffers from amnesia and was highly acclaimed for her perfect representation of the 1940s vintage femme fatale.

In 2000, Connelly appeared in several memorable films of her career, which included the dramatic love story Waking the Dead (2000), playing Sarah Williams, an activist killed by a car bomb in Minneapolis while she was driving Chilean refugees, followed by a breakthrough part in Darren Aranofsky's highly applauded independent film Requiem for a Dream (2000), a tale about the haunting lives of drug addicts and the subsequent process of decadence and destruction, in which her performance earned her a Spirit Award Nomination. However, it was her role in Ron Howard's A Beautiful Mind (2001) that possibly gave Connelly her greatest mainstream success. Starring opposite Russell Crowe, she appeared as Alicia Nash, the caring and enduring wife of John Nash, a schizophrenic man, who eventually overcame his mental problem and won the Nobel Prize in 1994. Before filming, Jenifer met the real Alicia Nash to learn about her life, which helped her to portray the character. The film was a critical and commercial success and Jenifer’s performance in the film earned her an Academy Award, a Golden Globe and also a BAFTA Award for Best Supporting Actress.

Connelly next played Betty Ross, a scientist and the former love interest of hero Bruce Banner, in Ang Lee's moderately successful film Hulk (2003), appeared as Kathy Nicolo, an abandoned wife whose inherited house is sold at auction in House of Sand and Fog (2004), portrayed the role of Dahlia, a frightened young woman traumatized by her past in the psychological thriller Dark Water (2005), played Kathy Adamson to share the screen with Kate Winslet in Little Children (2006), co-starred opposite Leonardo DiCaprio and portraying journalist Maddy Bowen in Blood Diamond (2006). Her other films during the decade included Reservation Road (2007), The Day the Earth Stood Still (2008) and Creation (2009), in which she enacted the role of Emma Darwin, the wife of Charles Darwin.

The subsequent important films of Jennifer Connelly during the 2010s include, among others, Dustin Lance Black’s Virginia (2010), in which she portrayed the title role of Virginia, a mentally unstable woman; in George Ratliff's Salvation Boulevard (2011) as Gwen Vandermeer; in the family drama Stuck in Love (2012), alongside Greg Kinnear and playing the ex-wife of Kinnear's character, with whom he is obsessed and Aronofsky’s epic Noah (2014), playing the wife of the biblical figure Noah. After that, she starred with Ewan McGregor in American Pastoral (2016), played the wife of a firefighter in Only the Brave (2017) and also appeared in the science-fiction thriller Alita: Battle Angel (2019). Recently, Jennifer appeared in the action blockbuster film Top Gun: Maverick (2022), a sequel to the 1986 blockbuster, along with Tom Cruise.

In her personal life, Jennifer Connelly was involved in a relationship with her co-star Billy Campbell, while filming The Rocketeer and although they became engaged, eventually they broke up in 1996, after five years of togetherness. After that, she had a relationship with photographer David Dugan, with whom she has a son, born in 1997. Jennifer Connelly and Paul Bettany locked eyes for the first time while filming A Beautiful Mind and both of them felt an immediate connection, but they maintained only a friendly relationship, because during that time, Jennifer was in a relationship with actor Josh Charles. However, a few days later of the 9/11 incident, Paul proposed to her during a phone call and she agreed. They married on the 1st day of January 2003 in a private family ceremony in Scotland and have two children, a son, born in 2003, and a daughter, born in 2011.