Grace Patricia Kelly (November 12, 1929 – September 14, 1982), also known as Grace of Monaco, was an American actress and Princess of Monaco as the wife of Prince Rainier III from their marriage on April 18, 1956, until her death in 1982. Prior to her marriage, she achieved stardom in several significant Hollywood films in the early to mid-1950s. She received an Academy Award and three Golden Globe Awards, and was ranked 13th on the American Film Institute's 25 Greatest Female Stars list.

Kelly was born into a prominent Catholic family in Philadelphia. After graduating from the American Academy of Dramatic Arts in 1949, she began appearing in New York City theatrical productions and television broadcasts. Kelly made her film debut in Fourteen Hours (1951) and gained stardom from her roles in Fred Zinnemann's western film High Noon (1952), and John Ford's adventure-romance Mogambo (1953), the latter of which earned her the Academy Award for Best Supporting Actress nomination. She won the Academy Award for Best Actress for her performance in the drama The Country Girl (1954). Other notable works include the war film The Bridges at Toko-Ri (1954), the romantic comedy High Society (1956), and three Alfred Hitchcock suspense thrillers: Dial M for Murder (1954), Rear Window (1954), and To Catch a Thief (1955).

Kelly retired from acting at age 26 to marry Rainier and began her duties as Princess of Monaco. Grace and Rainier had three children: Princess Caroline, Prince Albert, and Princess Stéphanie. Princess Grace's charity work focused on young children and the arts. In 1964, she established the Princess Grace Foundation to support local artisans. Her organization for children's rights, AMADE Mondiale, gained consultive status within UNICEF and UNESCO. Her final film role was narrating The Children of Theatre Street (1977), which was nominated for an Academy Award for Best Documentary Feature.

She died at the age of 52 at Monaco Hospital, from injuries sustained in a car crash. Her son, Prince Albert, helped establish the Princess Grace Awards in 1984 to recognize emerging performers in film, theatre, and dance.

Grace Patricia Kelly was born on November 12, 1929, at Hahnemann University Hospital in Philadelphia, Pennsylvania, to an affluent and influential family. Her father, John B. Kelly Sr., was born to Irish immigrants; he won three Olympic gold medals for sculling. He owned a successful brickwork contracting company that was well known on the East Coast. As the Democratic Party nominee in the 1935 election for mayor of Philadelphia, he lost by the closest margin in the city's history. In later years, he served on the Fairmount Park Commission and, during World War II, was appointed by President Roosevelt as National Director of Physical Fitness. His brother Walter C. Kelly was a vaudeville star, who also made films for Metro-Goldwyn-Mayer and Paramount Pictures, and another brother named George was a Pulitzer Prize-winning dramatist, screenwriter, and director. He built the family home at 3901 Henry Ave in the East Falls, Philadelphia, neighborhood. The Kellys' former family home went up for sale for $1 million in June 2016. It wound up selling in September 2016 for $775,000.

Kelly's mother, Margaret Majer, was of German ancestry. Margaret had taught physical education at the University of Pennsylvania and had been the first woman to coach women's athletics at Penn. She also modeled for a time in her youth. After marrying John Kelly in 1924, Margaret focused on being a homemaker until all her children were of school age, following which she began actively participating in various civic organizations. Patrilineally, Margaret descended from Prof. Johann Christian von Majer [de] (1741–1821) from Ludwigsburg, who worked as a political scientist, jurist and theologian, and was elected five times Rector of the University of Tübingen. Through him, Grace was descended from the Stauffenberg family — best known for Claus Schenk Graf von Stauffenberg, who attempted to assassinate Adolf Hitler — as well as from several other minor German noble families, including the von Plieningen, von Münchingen, von Ow, von Bettendorf, von Nippenburg, and von Roth families.

Kelly had two older siblings, Margaret and John Jr., and a younger sister, Elizabeth. The children were raised in the Catholic faith, and Grace continued to practice the faith until her death, with Rita Gam describing her as a "deeply religious person". Kelly grew up in a small, close-knit Catholic community. She was baptized and received her elementary education in the parish of Saint Bridget's in East Falls. Founded in 1853 by Saint John Neumann, the fourth Bishop of Philadelphia, Saint Bridget's was a relatively young parish, with families very familiar with one another. While attending Ravenhill Academy, a Catholic girls' school, Kelly modeled fashions at local charity events with her mother and sisters. In 1942, at the age of 12, she played the lead in Don't Feed the Animals, a play produced in East Falls by the Old Academy Players.

In May 1947, Kelly graduated from Stevens School, a private institution in nearby Chestnut Hill, where she participated in drama and dance programs. Her graduation yearbook listed her favorite actress as Ingrid Bergman and her favorite actor as Joseph Cotten. Written in the "Stevens' Prophecy" section was "Miss Grace P. Kelly – a famous star of stage and screen". Owing to her low mathematics scores, Kelly was rejected by Bennington College in July 1947. Despite her parents' initial disapproval, Kelly decided to pursue her dreams of becoming an actress. Her father was particularly displeased with her decision, as he viewed acting as "a slim cut above streetwalker" at the time. In 1947, Kelly signed with the Walter Thornton Model Agency gracing the covers of magazines.