Witold Marian Gombrowicz (August 4, 1904 – July 24, 1969) was a Polish writer and playwright. His works are characterised by deep psychological analysis, a certain sense of paradox and absurd, anti-nationalist flavor. In 1937, he published his first novel, Ferdydurke, which presented many of his usual themes: problems of immaturity and youth, creation of identity in interactions with others, and an ironic, critical examination of class roles in Polish society and culture.

He gained fame only during the last years of his life, but is now considered one of the foremost figures of Polish literature. His diaries were published in 1969 and are, according to the Paris Review, "widely considered his masterpiece", while Cosmos is considered, according to The New Yorker, "his most accomplished novel". He was nominated for the Nobel Prize in Literature four times, from 1966 to 1969.

Gombrowicz was born in Małoszyce near Opatów, then in Radom Governorate, Congress Poland, Russian Empire, to a wealthy gentry family of the Kościesza coat of arms. He was the youngest of four children of Jan Onufry and Antonina (née Ścibor-Kotkowska of the Ostoja coat of arms). In an autobiographical piece, A Kind of Testament, he wrote that his family had lived for 400 years in Lithuania on an estate between Vilnius and Kaunas but were displaced after his grandfather was accused of participating in the January Uprising of 1863. He later described his family origins and social status as early instances of a lifelong sense of being "between" (entre). In 1911 his family moved to Warsaw. After completing his education at Saint Stanislaus Kostka's Gymnasium in 1922, Gombrowicz studied law at Warsaw University, earning a MJur in 1927. He spent a year in Paris, where he studied at the Institute of Higher International Studies (French: Institut des Hautes Etudes Internationales). He was less than diligent in his studies, but his time in France brought him in constant contact with other young intellectuals. He also visited the Mediterranean.

When Gombrowicz returned to Poland, he began applying for legal positions with little success. In the 1920s he started writing. He soon rejected the legendary novel, whose form and subject matter were supposed to manifest his "worse" and darker side of nature. Similarly, his attempt to write a popular novel in collaboration with Tadeusz Kępiński was a failure. At the turn of the 1920s and 1930s, Gombrowicz began to write short stories, later printed under the title Memoirs of a Time of Immaturity, edited by Gombrowicz and published under the name Bacacay, the street where he lived during his exile in Argentina. From the moment of this literary debut, his reviews and columns began appearing in the press, mainly the Kurier Poranny (Morning Courier). Gombrowicz met with other young writers and intellectuals, forming an artistic café society in Zodiak and Ziemiańska, both in Warsaw. The publication of Ferdydurke, his first novel, brought him acclaim in literary circles.

Just before the outbreak of the Second World War, Gombrowicz took part in the maiden voyage of the Polish transatlantic liner MS Chrobry to South America. When he learned of the outbreak of war in Europe, he decided to wait in Buenos Aires until it was over; he reported to the Polish legation in 1941 but was considered unfit for military duties. He stayed in Argentina until 1963—often, especially during the war, in poverty.

At the end of the 1940s Gombrowicz was trying to gain a position in Argentine literary circles by publishing articles, giving lectures at the Fray Mocho café, and, finally, by publishing in 1947 a Spanish translation of Ferdydurke, with the help of friends including Virgilio Piñera. This version of the novel is now considered a significant event in the history of Argentine literature, but at the time of its publication it did not bring Gombrowicz any great renown, nor did the 1948 publication of his drama Ślub in Spanish (The Marriage, El Casamiento). From December 1947 to May 1955 Gombrowicz worked as a bank clerk in Banco Polaco, the Argentine branch of Bank Pekao, and formed a friendship with Zofia Chądzyńska, who introduced him to Buenos Aires's political and cultural elite. In 1950 he started exchanging letters with Jerzy Giedroyc, and in 1951 he began to publish work in the Parisian journal Culture, in which fragments of Dziennik (Diaries) appeared in 1953. In the same year he published a volume of work that included Ślub and the novel Trans-Atlantyk, in which the subject of national identity on emigration was controversially raised. After October 1956 four of Gombrowicz's books appeared in Poland and brought him great renown, even though the authorities did not allow the publication of Dziennik (Diary).

Gombrowicz had affairs with both men and women. In his later serialised Diary (1953–69) he wrote about his adventures in the homosexual underworld of Buenos Aires, particularly his experiences with young men from the lower class, a theme he picked up again when interviewed by Dominique de Roux in A Kind of Testament (1973).

In the 1960s Gombrowicz became recognised globally, and many of his works were translated, including Pornografia (Pornography) and Kosmos (Cosmos). His dramas were staged in theatres around the world, especially in France, Germany and Sweden.