Paltrow made her acting debut on stage in 1990 and started appearing in films in 1991. She gained early notice for her work in films such as Se7en (1995), Emma (1996), in which she played the title role, and Sliding Doors (1998). She garnered worldwide recognition through her performance in Shakespeare in Love (1998), for which she won the Academy Award for Best Actress, a Golden Globe Award and two Screen Actors Guild Awards, for Outstanding Lead Actress and as a member of the Outstanding Cast. Since then, Paltrow has portrayed supporting as well as lead roles in films such as The Talented Mr. Ripley (1999), Shallow Hal (2001) and Proof (2005), for which she earned a Golden Globe nomination as Best Actress in Motion Picture Drama. In 2008, she appeared in the highest grossing movie of her career, the superhero film Iron Man, and then reprised her role as Pepper Potts in its sequel, Iron Man 2 (2010). Paltrow has been the face of Estée Lauder's Pleasures perfume since 2005.

Paltrow was born in Los Angeles, California, the daughter of Blythe Danner, an actress, and Bruce Paltrow, a film and television director and producer. Paltrow's father was of Ashkenazi Russian Jewish descent and her mother is a Quaker of Pennsylvania Dutch ancestry. Paltrow's paternal great-grandfather, whose surname was "Paltrowicz", was a rabbi in little Nowogród, Poland. Paltrow was raised in Santa Monica, where she attended Crossroads School before moving and enrolling in The Spence School, a private girls' school in New York City. Later she briefly studied art history at the University of California, Santa Barbara, before dropping out to act. Paltrow has a younger brother, Jake Paltrow, and is a cousin of actress Katherine Moennig and Congresswoman Gabrielle Giffords (AZ-08). She is an "adopted daughter" of Talavera de la Reina (Spain), where at 15 she spent a year as an exchange student and learned to speak Spanish. Paltrow was a childhood friend of Saturday Night Live's Maya Rudolph.

Paltrow made her professional stage debut in 1990. Her film debut followed next year with Shout (1991), starring John Travolta; later that year, she appeared in Hook (1991), as Young Wendy. Paltrow then had minor roles in Malice (1993) and Flesh and Bone (1993). She was next cast in a supporting role in Se7en (1995) alongside Brad Pitt and Morgan Freeman, which earned her a Satellite Award nomination. The film was successful commercially and critically. In 1996, she played the title character in Emma to critical acclaim,[citation needed] particularly in the United Kingdom, where her perfection of the English accent was appreciated.[citation needed]

In 1998, Paltrow starred in Shakespeare in Love, portraying the fictional love of William Shakespeare, played by Joseph Fiennes. The film earned more than US$100 million in box office receipts in the United States and Paltrow gained critical acclaim for her portrayal. Entertainment Weekly commented, "Best of all is Gwyneth Paltrow, who, at long last, has a movie to star in that's as radiant as she is." The New York Times summed up her turn as Viola as such: "Gwyneth Paltrow, in her first great, fully realized starring performance, makes a heroine so breathtaking that she seems utterly plausible as the playwright's guiding light." The award-winning Shakespeare in Love earned Paltrow the award for Outstanding Performance by a Female Actor in a Leading Role from the Screen Actors Guild and the Academy Award for Best Actress, among other honors.

In 1999, Paltrow co-starred in The Talented Mr. Ripley, which earned $80 million domestically and received positive reviews. She showcased her singing ability in 2000's Duets, which was directed by her father and co-starred singer Huey Lewis. The same year, Paltrow co-starred with Ben Affleck in the romantic drama Bounce as Abby Janello. She was then part of an ensemble cast, as Margot Tenenbaum, in The Royal Tenenbaums (2001). Also in 2001, she starred with Jack Black in the comedy Shallow Hal, where she played both roles, slim and fat Rosemary, and had to wear a specially designed 25 pound fatsuit and heavy make-up.

Since the Oscar for Shakespeare in Love, Paltrow's film success has been less noteworthy. She said she was unequipped for the pressure, leading to several bad movie choices, agreeing with peers who believe the win is, in some ways, a curse. In The Guardian, she said she divided her career into movies for love and films for money: The Royal Tenenbaums, Proof, and Sylvia fell into the former category, while she did View from the Top and Shallow Hal for the latter.

As a new mother, Paltrow did not work much from 2004 to 2007. She appeared in the 2005 film Proof as a young protagonist, mathematician and daughter Catherine. The movie is based on the play of the same name, in which Paltrow also played the same character at London's Donmar Warehouse in 2002. In 2006, she had small roles in Running With Scissors and Infamous, in which she sang Cole Porter's "What Is This Thing Called Love?".

In 2008, she appeared in Iron Man as Pepper Potts, Stark's closest friend, budding love interest, and business partner after Pepper replaced Obadiah Stane as CEO of Stark Industries. The film is her largest grossing movie ever, earning more than US$ 585 million at the worldwide box office. Paltrow said she was hesitant to appear in a big-budget project but she was won over by Robert Downey Jr., the film's lead, and director Jon Favreau. Paltrow recalled a conversation with Downey, saying:

In 2010, she reprised her role in the sequel to Iron Man, Iron Man 2. Later in 2010, she will appear in the country musical, Country Strong. Paltrow will next shoot for Steven Soderbergh's Virus thriller Contagion, in which she is part of an ensemble cast.

Paltrow is a Save the Children artist ambassador, raising awareness about World Pneumonia Day. She is on the board of the Robin Hood Foundation, a charitable organization that works to alleviate poverty in New York City. In February 2009, Paltrow received a Grammy nomination for her reading of the classic bear books of author Bill Martin, Jr..