Born in Wabbaseka, Arkansas, Cleaver moved with his family to Phoenix and then to Los Angeles. He has a son, Riley Cleaver, with a girlfriend. In 1967 he married Kathleen Neal Cleaver; they divorced in 1987. They had a son, Ahmad Maceo Eldridge Cleaver, and a daughter, Joju Younghi Cleaver.

As a teenager he was involved in petty crime and spent time in detention centers. In 1957 Cleaver was arrested for committing rape and was convicted of assault with intent to murder.

Soul on Ice

While in prison, he wrote a number of philosophical and political essays, first published in Ramparts magazine and then in book form as Soul on Ice, which were highly influential in the black power movement. In them, Cleaver traces his own development from a "supermasculine menial" to a radical black liberationist.

Within the text of the book, Cleaver acknowledges the serial rape of several white and black women, and states that "rape was an insurrectionary act," although he also describes how following his incarceration, he came to reject this line of thinking.

The essays in Soul on Ice are divided in four thematic sections:

• Letters from Prison - on black existence and human 'being'.
• Blood of the Beast - on black liberation theory.
• Prelude to Love - Three Letters - a serenade to his defense lawyer Beverly Axelrod.
• White Woman, Black Man - a critique of the racist and socio-political implications of sexual 'being'.

Black Panther Party

Eldridge Cleaver was released from prison in 1966, after which he joined the Oakland-based Black Panther Party, serving as Minister of Information, or spokesperson. What initially attracted Cleaver to the Panthers as opposed to other prominent groups was their commitment to armed struggle.

In 1967, Eldridge Cleaver, along with Marvin X, Ed Bullins and Ethna Wyatt, formed the Black House political/cultural center in San Francisco. Amiri Baraka, Sonia Sanchez, Askia Toure, Sarah Webster Fabio, Art Ensemble of Chicago, Avotja, Reginald Lockett, Emory Douglas, Samuel Napier, Bobby Hutton, Huey Newton, and Bobby Seale were Black House regulars.

He was a Presidential candidate in 1968 on the ticket of the Peace and Freedom Party. Cleaver and his running mate Judith Mager received 36,571 votes (0.05%). Later that year, he was shot during an ambush of Oakland police in which fellow Black Panther member Bobby Hutton was killed and two police officers were injured. Cleaver later said that he had led the Panther group on a deliberate ambush of the police officers, thus provoking the shoot-out. Charged with attempted murder, he jumped bail to flee to Cuba and later went to Algeria. Following Timothy Leary's Weather Underground assisted prison escape, Leary stayed with Cleaver in Algeria; however, Cleaver placed Leary under "revolutionary arrest" as a counter-revolutionary for promoting drug use. Cleaver later left Algeria and spent time in France.

Eldridge Cleaver and Huey Newton eventually fell out with each other over the necessity of armed struggle as a response to COINTELPRO and other actions by the government against the Black Panthers and other radical groups. Cleaver advocated the escalation of armed resistance into urban guerilla warfare, while Newton suggested the best way to respond to was to put down the gun, which he felt alienated the Panthers from the rest of the Black community, and focus on more pragmatic reformist activity.

Cleaver returned to the United States in 1975, and subsequently renounced the Black Panthers. Legal wrangling ended in his being sentenced to probation for assault.

Soul on Fire

Playing on the title of his most famous book, Soul on Ice, Cleaver published Soul on Fire in 1978. Cleaver revealed several aspects of his exile in Algeria:

• Cleaver was supported by regular stipends from the Democratic Republic of Vietnam, which the United States was then bombing.
• Cleaver was followed by other former criminals turned revolutionaries, many of whom hijacked planes to get to Algeria. The Algerians expected Cleaver to keep his protégés in line, which he described as increasingly difficult as their increasing numbers stretched his North Vietnamese allowance to the breaking point. Cleaver organized a stolen car ring to employ his revolutionary protégés, stealing cars in Europe to sell in Africa. Around this time Cleaver discovered his wife had a lover. The lover was subsequently murdered by persons unknown.
• Cleaver eventually fled Algeria out of fear for his life. He could no longer control his protégés and the Algerian police were cracking down on them. He subsequently lived underground for a time in France.
• Cleaver became a "born again" Christian during his year of isolation, while living underground. He later led a short-lived revivalist ministry called Eldridge Cleaver Crusades

Later life

In the early 1980s, Cleaver became disillusioned with what he saw as the commercial nature of mainstream evangelical Christianity and examined alternatives, including Sun Myung Moon's campus ministry organization CARP, and Mormonism. Cleaver was baptized into The Church of Jesus Christ of Latter-day Saints on December 11, 1983, periodically attended regular services, lectured by invitation at LDS gatherings, and was a member of the church in good standing at the time of his death in 1998.

By the 1980s, Cleaver had become a conservative Republican. He appeared at various Republican events and spoke at a California Republican State Central Committee meeting regarding his political transformation. In 1986 Cleaver embarked on an unsuccessful campaign to win the United States Senate seat held by Democratic incumbent Sen. Alan Cranston, as he received less than two percent of the vote in the Republican Party primary.

Eldridge Cleaver died at Pomona Valley Hospital Medical Center on May 1, 1998. His family asked that the hospital not reveal the cause of death, although he was known to have diabetes and prostate cancer. He is buried at Mountain View Cemetery in Altadena, California.

• Christian rock pioneer Larry Norman wrote his song Soul on Fire in 1968 based on Cleaver's story, and after his return from Europe, offered it to him for use to raise funds for his legal defense, but Cleaver refused as he believed the lyrics questioned the sincerity of his conversion. After Cleaver's conversion to the Moonies and later Mormonism, Norman released an alternate version of the song without any reference to Cleaver.

• In the season 3 premiere of Fringe, the alternate universe, known as "Over There", is shown to have a park with the sign Martin Luther King, Eldridge Cleaver, Memorial Park, "We Have a Dream" in New York City.