Born in Wabbaseka, Arkansas, as a child Cleaver moved with his family to Phoenix and then to Los Angeles. He was the son of Leroy Cleaver and Thelma Hattie Robinson. He had 4 siblings: Wilhelima Marie, Helen Grace, James Weldon, and Theophilus Henry. In 1967, he married Kathleen Neal Cleaver; they divorced in 1987. They had a son, Ahmad Maceo Eldridge Cleaver, and a daughter, Jojuyounghi Cleaver.  As a teenager, he was involved in petty crime and spent time in youth detention centers. At the age of eighteen, he was convicted of a felony drug charge and sent to the adult prison at Soledad. In 1958, he was convicted of rape and assault with intent to murder and eventually served time in Folsom and San Quentin prisons. While in prison, he was given a copy of the Communist Manifesto. The book justified all his feelings of rebellion and hatred. Cleaver petitioned for habeas corpus to the Solano County Court and was granted it along with a release of a $50,000 bail.

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. In the essays, Cleaver traces his own development from a “supermasculine menial” to a radical black liberationist, and his essays became highly influential in the black power movement. In the most controversial part of the book, Cleaver acknowledges committing acts of rape, stating that he initially raped black women in the ghetto “for practice” and then embarked on the serial rape of white women. He described these crimes as politically inspired, motivated by a genuine conviction that the rape of white women was “an insurrectionary act”. When he began writing Soul on Ice, he unequivocally renounced rape and all his previous reasoning about it. However, he refused to show any remorse for his career as a rapist, or acknowledge any debt to society, claiming in Soul on Ice that “the blood of Vietnamese peasants has paid off all my debts”.

The essays in Soul on Ice are divided into four thematic sections: “Letters from Prison”, describing Cleaver’s experiences with and thoughts on crime and prisons; “Blood of the Beast”, discussing race relations and promoting black liberation ideology; “Prelude to Love – Three Letters”, love letters written to Cleaver’s attorney, Beverly Axelrod; and “White Woman, Black Man”, on gender relations, black masculinity, and sexuality.

Eldridge Cleaver was released from prison on December 12, 1966. At this time President John F. Kennedy and Malcolm X were dead. The Black Panther Party was only two months old. He then 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, Avotcja, Reginald Lockett, Emory Douglas, Samuel Napier, Bobby Hutton, Huey Newton, and Bobby Seale were Black House regulars.  Cleaver was a presidential candidate in 1968 on the ticket of the Peace and Freedom Party. Having been born on August 31, 1935, Cleaver would not have been the requisite 35 years of age until more than a year after Inauguration Day 1969. (Although the Constitution requires that the President be 35 years of age, it does not specify if he must have reached that age at the time of nomination, or election, or inauguration.) Courts in both Hawaii and New York held that he could be excluded from the ballot because he could not possibly meet the Constitutional criteria. Cleaver and his running mate Judith Mage received 36,571 votes (0.05%).

Also in 1968, Cleaver led an ambush of Oakland police officers, during which two officers were wounded. In the aftermath of the ambush, Cleaver was wounded and seventeen year old Black Panther member Bobby Hutton was killed. The eight Panthers who ambushed the police department had two objectives: bust Huey out and kill some cops. Charged with attempted murder, he jumped bail to flee to Cuba. In Cuba, he received red carpet treatment from Fidel Castro. Cleaver was set up in a Havana penthouse with his own personal maid and cook. The penthouse was stocked with all the food, rum, and cigars he would need. The hospitality soon ended. Castro had received information that the CIA had infiltrated the Black Panther Party and Castro could no longer trust them. Cleaver then decided to head to Algeria, sending word to his wife to meet him there. Cleaver had set up an international office for the Black Panthers in Algeria, but then in 1971 he was kicked out of the party. 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, became a born again Christian, and subsequently renounced his ultra-radical past. With regard to the attempted murder charge stemming from the armed Panther attack on Oakland police in 1968, legal wrangling ended in Cleaver being sentenced to probation for assault. In 1980, he admitted that he had led the Panther group on a deliberate ambush of the police officers, thus provoking the shootout.

Playing on the title of Soul on Ice, Cleaver published Soul on Fire in 1978. Cleaver made several claims regarding his exile in Algeria: he claimed he was supported by regular stipends from the government of North Vietnam, which the United States was then bombing. Cleaver stated that he was followed by other former criminals turned revolutionaries, many of whom hijacked planes to get to Algeria. Apparently, 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, stealing cars in Europe to sell in Africa. Around this time, Cleaver discovered his wife had a lover, who was subsequently murdered. 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 then lived for a time in France. Cleaver became a born again Christian during his year of isolation while living underground.

In the early 1980s, Cleaver became disillusioned with what he saw as the commercial nature of evangelical Christianity and examined alternatives, including Sun Myung Moon’s campus ministry organization CARP, and Mormonism. He later led a short-lived revivalist ministry called Eldridge Cleaver Crusades, “a hybrid synthesis of Islam and Christianity he called ‘Christlam'”, along with an auxiliary called the Guardians of the Sperm. Then he converted to Mormonism.  Cleaver was baptized into The Church of Jesus Christ of Latter-day Saints (LDS Church) 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 1984, he ran for election to the Berkeley City Council but lost. Undaunted, he promoted his candidacy in the Republican Party primary for the 1986 Senate race but was again defeated.  In 1988, Cleaver was placed on probation for burglary and was briefly jailed later in the year after testing positive for cocaine. He entered drug rehabilitation for a stated crack cocaine addiction two years later, but was arrested for possession by Oakland and Berkeley Police in 1992 and 1994. Shortly after his final arrest, he moved to Southern California, falling into poor health.

Cleaver died at Pomona Valley Hospital Medical Center in Pomona, California on May 1, 1998 at 6:20 am.  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.