Lorraine Vivian Hansberry (May 19, 1930 – January 12, 1965) was an American playwright and writer. She was the first Black American female author to have a play performed on Broadway. Her best-known work, the play A Raisin in the Sun, highlights the lives of Black Americans in Chicago living under racial segregation. The title of the play was taken from the poem "Harlem" by Langston Hughes: "What happens to a dream deferred? Does it dry up like a raisin in the sun?" At the age of 29, she won the New York Drama Critics' Circle Award – making her the first Black American dramatist, the fifth woman, and the youngest playwright to do so. Hansberry's family had struggled against segregation, challenging a restrictive covenant in the 1940 U.S. Supreme Court case Hansberry v. Lee.

After she moved to New York City, Hansberry worked at the Pan-Africanist newspaper Freedom, where she worked with other Black intellectuals such as Paul Robeson and W. E. B. Du Bois. Much of her work during this time concerned the African struggles for liberation and their impact on the world. Hansberry also wrote about being a lesbian and the oppression of gay people. She died of pancreatic cancer at the age of 34 during the Broadway run of her play The Sign in Sidney Brustein's Window in 1965. Hansberry inspired the Nina Simone song "To Be Young, Gifted and Black", whose title-line came from Hansberry's autobiographical play.

Lorraine Hansberry was the youngest of four children born to Carl Augustus Hansberry, a successful real-estate broker, and Nannie Louise (born Perry), a driving school teacher and ward committeewoman.

In 1938, her father bought a house in the Washington Park Subdivision of the South Side of Chicago, incurring the wrath of some of their white neighbors. The latter's legal efforts to force the Hansberry family out culminated in the U.S. Supreme Court's decision in Hansberry v. Lee, 311 U.S. 32 (1940). The restrictive covenant was ruled contestable, though not inherently invalid; the enforcement of such covenants were eventually ruled unconstitutional in Shelley v. Kraemer, 334 U.S. 1 (1948).

Carl Hansberry was also a supporter of the Urban League and NAACP in Chicago. Both Hansberrys were active in the Chicago Republican Party. Carl died in 1946 when Lorraine was fifteen years old; "American racism helped kill him," she later said.

The Hansberrys were routinely visited by prominent black people, including sociology professor W. E. B. Du Bois, poet Langston Hughes, singer, actor, and political activist Paul Robeson, musician Duke Ellington, and Olympic gold medalist Jesse Owens. Carl Hansberry's brother, William Leo Hansberry, founded the African Civilization section of the History Department at Howard University. Lorraine was taught: "Above all, there were two things which were never to be betrayed: the family and the race."

Lorraine Hansberry has many notable relatives, including director and playwright Shauneille Perry, whose eldest child is named after her. Her grandniece is the actress Taye Hansberry. Her cousin is the flautist, percussionist, and composer Aldridge Hansberry.

Hansberry was the godmother to Nina Simone's daughter Lisa.