Ōe was born in
Ōse (大瀬村 Ōse-mura), a village now in
Uchiko, Ehime Prefecture on
Shikoku. He was the third son of seven children. Ōe's grandmother taught him art and oral performance. His grandmother died in 1944, and later that year, Ōe's father died in the
Pacific War. Ōe's mother became his primary educator, buying him books such as
The Adventures of Huckleberry Finn and
The Wonderful Adventures of Nils, whose impact Ōe says "he will carry to the grave".
Ōe remembers his elementary school teacher claiming that Emperor
Hirohito was a living god, and asking him every morning, "What would you do if the emperor commanded you to die?" Ōe always replied, "I would die, sir. I would cut open my belly and die." At home in bed at night he would acknowledge his reluctance to die and feel ashamed.
 After the war, he realized he had been taught lies and felt betrayed. This sense of betrayal later appeared in his writing.
Ōe attended high school in
Matsuyama. At the age of 18, he made his first trip to Tokyo and in the following year began studying French Literature at
Tokyo University under the direction of Professor Kazuo Watanabe, a specialist on
François Rabelais. Oe began publishing stories in 1957, while still a student, strongly influenced by contemporary writing in France and the United States. He married in February 1960. His wife, Yukari, was the daughter of film director
Mansaku Itami and sister of film director
Juzo Itami. The same year he met
Mao Zedong on a trip to China. He also went to Russia and Europe the following year, visiting
Sartre in Paris.
In 1961, Ōe's novellas Seventeen and The Death of a Political Youth were published by a Japanese literary magazine. Both were inspired by seventeen-year-old
Yamaguchi Otoya, who assassinated the chairman of Japan's Socialist Party in 1960, and then killed himself in prison three weeks later.
Yamaguchi had admirers among the extreme
right wing who were angered by The Death of a Political Youth and both Ōe and the magazine received
death threats day and night for weeks. The magazine soon apologized to offended readers, but Ōe did not.
Ōe lives in Tokyo. He has three children; the eldest son,
Hikari, has been brain-damaged since his birth in 1963, and his disability has been a recurring motif in Ōe's writings since.
In 1994 Ōe won the
Nobel Prize in Literature and was named to receive Japan's
Order of Culture. He refused the latter because it is bestowed by the
Emperor. Ōe said, "I do not recognize any authority, any value, higher than democracy." Once again, he received threats.
Ōe at a 2013 antinuclear demonstration in Tokyo
In 2005, two retired Japanese military officers sued Ōe for
libel for his 1970 essay, Okinawa Notes, in which he had written that members of the Japanese military had coerced masses of Okinawan civilians into committing suicide during the
Allied invasion of the island in 1945. In March 2008, the
Osaka District Court dismissed all charges against Ōe. In this ruling, Judge Toshimasa Fukami stated, "The military was deeply involved in the
mass suicides". In a news conference following the trial, Ōe said, "The judge accurately read my writing."
Ōe has been involved with
anti-nuclear campaigns and has written books regarding the
atomic bombings of Hiroshima and Nagasaki and the
Hibakusha. Following the 2011
Fukushima nuclear disaster, he urged Prime Minister
Yoshihiko Noda to "halt plans to restart nuclear power plants and instead abandon nuclear energy".
 Ōe has said Japan has an "
ethical responsibility" to abandon nuclear power in the aftermath of the Fukushima nuclear disaster, just as it renounced war under its postwar
Constitution. He has called for "an immediate end to nuclear power generation and warned that Japan would suffer another nuclear catastrophe if it tries to resume nuclear power plant operations". In 2013, he organized a mass demonstration in Tokyo against nuclear power.
 Ōe has also criticized moves to amend
Article 9 of the Constitution, which forever renounces war.