Born in Alabama in 1944 to a middle class family, Davis was the oldest of three children. She attended the segregated schools of Alabama until the age of 15, when she received a scholarship from the American Friends Service Committee to attend Elizabeth Irwin High School, a progressive private school in New York City.

After graduating from high school Davis won a scholarship to Brandeis University, where she majored in French literature. She spent her junior year (1962) at the Sorbonne in Paris, witnessed firsthand the Algerian conflict being waged in the streets there, and attended the Communist Youth Festival in Helsinki which had a significant impact on her political development. In 1965 she graduated from Brandeis with honors and went to Frankfurt, Germany to study philosophy at Goethe University. At the University she continued her activism and joined a socialist student group opposed to the war in Vietnam. In her autobiography, Davis notes that she spent time in East Germany, which served to deepen her commitment to socialism.

Upon her return to the U.S. Davis joined the Black liberation movement and the struggle against the Vietnam War in San Diego and Los Angeles.

According to her autobiography, Davis first became aware of the Soledad Brothers after reading a February 1970 article in the Los Angeles Times. She accepted the co-chair of the Soledad Brothers Defense Committee and as a result of her activities and subsequent visits to Soledad Prison, Davis befriended the families of the Soledad Brothers and corresponded with the three men.

On August 3, 1970, Jonathan Jackson, George Jackson's seventeen year old brother, tried to assist James McClain, on trial for an alleged attempt to stab an officer, escape from the courthouse. During the escape attempt the judge and Jackson were killed in a shootout with the police; one juror and the district attorney were wounded. The guns used in the kidnapping were allegedly traced to Davis, implicating her in the escape attempt. A California warrant was issued for Davis' arrest in which she was charged as an accomplice to murder, kidnapping, and conspiracy. She fled Los Angeles and evaded arrest by seeking refuge in several places including New York City. A federal fugitive warrant was subsequently issued and she was placed on the Federal Bureau of Investigation's ten most wanted list.

Two months later Davis was captured in New York City. While awaiting trial, and after a few joint court appearances, Davis separated her case from Magee's and their cases were tried separately. Magee wanted his trial held in a federal court while Davis wanted her trial held in California's state court. Davis' trial was moved from Marin County, a primarily white upper middle class community to San Jose, California which was an ethnically and racially more diverse city, in an effort to secure a fair trial with a less biased jury.

Almost immediately a groundswell of support developed in favor of Davis' release. Davis in particular, received widespread national and international support from the black community, liberals and the progressive left. The Communist Party mounted a major political campaign and held rallies in the United States and abroad, published articles, pamphlets and posters, issued petitions, distributed postcards, and requested that the public mail cards and letters on Davis' behalf.

After a trial by jury, consisting of eleven whites and one Latino, Davis was acquitted of all charges. Following her acquittal Davis taught at San Francisco State University for several years. From 1973 until the early 1990s she served on the board of the National Alliance Against Racism and Political Repression, an organization she helped found with Charlene Mitchell. In the Fall of 1995, she was appointed to the University of California at Santa Cruz Presidential Chair and became a consultant to the Ph.D program at UCSC where she continues to teach. Davis has written several books on gender and class issues, the prison system and its impact on minority populations, and is a major figure in the orthodox Communist Party.