Shields's career as a model began in the 1960s as an infant, and she continued as a successful child model throughout the 1970s. In early 1980 (at age 14), Shields was the youngest fashion model to ever appear on the cover of the top fashion publication Vogue magazine. Later that same year (at age 15), Shields appeared in controversial print and TV ads for Calvin Klein jeans. The TV ad included her saying the famous tagline, "Nothing comes between me and my Calvins." By the age of 16, Shields had become one of the most recognizable faces in the world because of her dual career as a provocative fashion model and controversial child actress.

Shields's film career began in 1978 with her appearance in Louis Malle's Pretty Baby, a movie in which she played a child living in a brothel (and in which there were numerous nude scenes). Because she was only 12 when the film was released, and possibly 11 when it was filmed, questions were raised about child pornography. This was followed by a slightly less controversial, but also less notable film, Wanda Nevada (1979).

After two decades of movies, her best-known films are still arguably The Blue Lagoon (1980) (which included more nude scenes, but Shields later testified before a U.S. Congressional inquiry that older body doubles were used in some of them), and Endless Love (1981). She won the People's Choice Award in the category of Favorite Young Performer in four consecutive years from 1981 to 1984.

Shields put her film career on hold to attend Princeton University from 1983 to 1987, graduating with a degree in French literature. Her senior thesis was titled The Initiation: From Innocence to Experience: The Pre-Adolescent/Adolescent Journey in the Films of Louis Malle, "Pretty Baby" and "Lacombe Lucien."

In 1984, she was Michael Jackson's date to the Grammy Awards and also dated him for a brief period.

Shields has appeared in a number of television shows, the most successful being the NBC sitcom Suddenly Susan, in which she starred from 1996 until 2000, and which earned her a People's Choice Award in the category of Favorite Female Performer in a New Television Series in 1997.

Shields has appeared in many on-stage productions, mostly musical revivals, including Grease, Cabaret, Wonderful Town and Chicago on Broadway; she also performed in Chicago in London's West End.

Shields made a couple of guest appearances on That '70s Show. She played Mrs. Burkhart, Jackie's (Mila Kunis) mother, who later was briefly involved with Donna's (Laura Prepon) father (played by Don Stark). Shields left That '70s Show when her character was written out.

Shields was born in New York City into an aristocratic family (on her father's side); her father was the late Francis Alexander Shields and her mother is Teri Shields (born Maria Theresia Schmonn). Brooke's parents divorced when she was a small child. Her father remarried Diana Lippert, the former wife of Thomas Gore Auchincloss (half-brother of Gore Vidal and stepbrother of Jacqueline Kennedy Onassis).

Brooke has three half sisters: Marina Torlonia Shields (who married Thomas William Purcell), Olympia, and Christiana Shields. Also, she has two stepsiblings: Diana Luise Auchincloss and Thomas Gore Auchincloss Jr.

Actor/comedian Eddie Murphy, in his concert film, Eddie Murphy: Raw, called Shields "the whitest woman in America". Her paternal grandparents are Francis Xavier Shields, a tennis star of Irish descent, and Italian princess Donna Marina Torlonia di Civitella-Cesi, who was a sister of Don Alessandro Torlonia, 5th Prince di Civitella-Cesi, husband of the spanish Infanta Doña Beatriz de Borbón y Battenberg (aunt of King Juan Carlos I of Spain). Their granddaughter, Sibilla Weiller (b. 1968), Brooke's cousin, married Prince Guillaume of Luxembourg (b. 1963), the youngest brother of Henri, Grand Duke of Luxembourg, in 1994.

Through her Italian grandmother, Shields is a descendant of Lucrezia Borgia, Holy Roman Emperor Charles V, Honoré I of Monaco and Henry IV of France. Shields is "a 23rd generation descendant of Francesco I Gattilusio, the founder of the Lesbian Gattilusii dynasty," according to the monograph "The Lesbos Island Ancestors of Prince Rainier of Monaco, Dr. Otto von Habsburg, Brooke Shields, and the Marquis de Sade."

Through her Irish grandfather, the branch of the Shields family from which Brooke Shields descends, traces its ancestry to William Shields, born 1600, at Lough Neagh in County Armagh and killed in County Antrim in 1655. He had four sons, William, James, Daniel, and John. William & James were deported by Cromwell to Barbados in 1655 (they may have been conscripted to serve in the invasion of Spanish America — the “Western Design” that collapsed at Hispaniola in that year). Both relocated to Middle Plantation (now Williamsburg, Virginia) in 1658 as indentured servants. James and his descendents became tavern-keepers. Shields Tavern is a restored public house in Colonial Williamsburg. John Shields, the gunsmith of the Lewis & Clark expedition was of this line as was United States President John Tyler through his mother. William migrated to Kent Country, Maryland where he gave rise to the prominent Tennessee political clan, the New Orleans family of white jazz musicians. The third brother, Daniel, was a Catholic partisan who would die in the Battle of the Boyne in 1690. His son, one of the Wild Geese, associated with the Spanish and wound up in Cuba as governor general. Other descendents include the Civil War General James Shields, who would become U.S. Senator in three different states. The youngest of the four sons, John (born 1650), died on his voyage to America in 1732. His son William Shields was fostered by the Kent County, Maryland cousins and would found Emmitsburg, Maryland. Among many notable descendents were Arthur Shields, a controversial 19th-century Presbyterian, who was expelled from Princeton University and from this branche belongs Brooke Shields.

When Shields was a young starlet in the 1980s, her romantic relationships were the subject of many tabloid articles. Among the celebrities she dated in her youth were Ted McGinley, who took her to her high school prom, Prince Albert II of Monaco and Michael Jackson, who took her as his date to the Grammy Awards (an event which provoked Murphy's joke about Shields' complexion). She was married from April 19, 1997 to April 9, 1999 to professional tennis player Andre Agassi. Since April 4, 2001 she has been married to television writer Chris Henchy. They have two daughters: Rowan Francis (b. May 15, 2003) and Grier Hammond (b. April 18, 2006). Coincidentally, Shields' second child was born on the same day and in the same hospital as the first child of Katie Holmes and Shields-critic Tom Cruise.

In the spring of 2005, Shields spoke to magazines and appeared on The Oprah Winfrey Show to publicize her battle with postpartum depression, an experience that included depression, thoughts of suicide, an inability to respond to her baby's needs, and delayed maternal bonding. The illness may have been triggered by a traumatic childbirth, the death of her father three weeks earlier, stress from in vitro fertilisation, a miscarriage, and a family history of depression, as well as the hormones and life changes brought on by childbirth. Her book, Down Came the Rain, discusses her experience.