Alexander Murray Palmer Haley was born to Simon Alexander, a college professor, and Bertha George (Palmer) Haley, a grammar school teacher, in Ithaca, New York on August 11, 1921. Haley spent much of his childhood on southern college campuses and with his relatives in Henning, Tennessee. Haley finished high school at 15 and attended college for two years before enlisting in the Coast Guard in 1939. At that time all blacks had to serve in the culinary department, so Haley enlisted as a messboy. World War II lengthened his tour and Haley was promoted to steward. He also married Nannie Branch, who he had met at a North Carolina port. After Pearl Harbor, Haley was assigned to a cargo-supply ship in the South Pacific, where he was promoted from steward to signalman. In 1945, he was recalled back to the States and assigned to Third (New York) District public relations. In 1950, Haley was made the Coast Guard's Chief Journalist (a position that had been created just for him). He also began selling his stories to such publications as This Week and Reader's Digest.

In 1954, Haley began writing stories of interest to the African-American population specifically. He was also transferred to San Francisco, California, where he continued to write. Haley retired from the Coast Guard in 1959 and achieved prominence in 1965 with his The Autobiography of Malcolm X. Shortly after this work was published, he approached his publishers at Doubleday with an idea for a project that would tell the story of his family in West Tennessee after the Civil War. Haley intended it to be a story about Henning, which he considered a good example of a place where blacks and whites could live side-by-side free of the interracial violence found in many other American cities.

As Haley began research on this project (initially titled "Before This Anger"), he became fascinated with his family's genealogy. After travelling around the United States visiting libraries and consulting with experts, Haley hypothesized that his great-great-great-great grandfather was kidnapped from the Gambia in the mid-1760's. He traveled to the Gambia in 1967, where he interviewed a griot (an African elder who maintains a tribe's oral history) named Fofana. Fofana's mother was of the Kinte family and Fofana informed Haley that the ancestor he had identified was Kunta Kinte, who was captured by slavers in 1767.

This genealogical breakthrough made Roots one of the most anticipated books of the twentieth century. It was finally published in 1976. ABC turned it into a miniseries, and in this form it reached the top of the Nielsen ratings. Haley was sued three times in connection with Roots: once by Margaret Walker Alexander (who contended that he had plagiarized her Jubilee), once by Harold Courlander (who claimed that Haley had plagiarized his The African), and once by Leonard S. Brown, Jr.

After the initial success of Roots, Haley created a mini-series called Roots: The Next Generation(s) and a documentary called My Search for Roots. He also wrote a two-act musical called The Way (focusing on what he considered the inanity of inter-racial struggle) and the books Queen (1993) and Henning. Haley died suddenly in Seattle, Washington (where he had come for a speaking engagement) on February 10, 1992. After his death, his farm in Clinton, Tennessee (which he was renovating in order to create a place where he could host symposiums and meetings) was auctioned to pay debts incurred during the final years of his life.