Ellroy was born in Los Angeles, California. His mother, Geneva Odelia (née Hilliker), was a nurse, and his father, Armand, was an accountant and a onetime business manager of Rita Hayworth. After his parents’ divorce, Ellroy relocated to El Monte, California, with his mother. When Ellroy was 10 years old, his mother was raped and murdered on June 22 1958. Ellroy later described his mother as “sharp-tongued [and] bad-tempered”, unable to keep a steady job, alcoholic and sexually promiscuous. His first reaction upon hearing of her death was relief: he could now live with his father, whom he preferred. The police never found the perpetrator, and the case remains unsolved. The murder, along with reading The Badge by Jack Webb (a book comprising sensational cases from the files of the Los Angeles Police Department, a birthday gift from his father), was an important event of Ellroy’s youth.

In 1981, Ellroy published his first novel, Brown’s Requiem, a detective story drawing on his experiences as a caddie. He then published Clandestine and Silent Terror (which was later published under the title Killer on the Road). Ellroy followed these three novels with the Lloyd Hopkins Trilogy. The novels are centered on Hopkins, a brilliant but disturbed LAPD robbery-homicide detective, and are set mainly in the 1980s.

After a second marriage in the mid-1990s to Helen Knode (author of the 2003 novel The Ticket Out), the couple moved from California to Kansas City in 1995. In 2006, after their divorce, Ellroy returned to Los Angeles. He is a self-described recluse who possesses very few technological amenities, including television, and claims never to read contemporary books by other authors, aside from Joseph Wambaugh’s The Onion Field, out of concern that they might influence his own. However, this does not mean that Ellroy does not read at all, as he claims in My Dark Places to have read at least two books a week growing up, eventually shoplifting more to satisfy his love of reading. He then goes on to say that he read works by Dashiell Hammett and Raymond Chandler.

In 1995, Ellroy published American Tabloid, the first novel in a series informally dubbed the “Underworld USA Trilogy” that Ellroy describes as a “secret history” of the mid-to-late 20th century. Tabloid was named TIME’s fiction book of the year for 1995. Its follow-up, The Cold Six Thousand, became a bestseller. The final novel, Blood’s a Rover, was released on September 22, 2009.

After publishing American Tabloid, Ellroy began a memoir, My Dark Places, based on his memories of his mother’s murder, the unconventional relationship he had with her, and his investigation of the crime. In the memoir, Ellroy mentions that his mother’s murder received little news coverage because the media were still fixated on the murder of mobster Johnny Stompanato, who was dating actress Lana Turner. Frank C. Girardot, a reporter for The San Gabriel Valley Tribune, accessed files on Geneva Hilliker Ellroy’s murder from detectives with Los Angeles Police Department. Based on the cold case file, Ellroy and investigator Bill Stoner worked the case but gave up after 15 months, believing any suspects to be dead. After the final pages of My Dark Places, a contact page is provided, stating: “The investigation continues. Information on the case can be forwarded to Detective Stoner either through the toll-free number, 1-800-717-6517, or his e-mail address, [email protected]” In 2008, The Library of America selected the essay “My Mother’s Killer” from My Dark Places for inclusion in its two-century retrospective of American True Crime.

In 2008, Daily Variety reported that HBO, along with Tom Hanks’s production company, Playtone, was developing American Tabloid and The Cold Six Thousand for either a miniseries or ongoing series. In a 2009 interview, Ellroy himself stated, “All movie adaptations of my books are dead.”

In a 2012 interview, when asked about how movie adaptations distort his books, he remarked, “[Film studios] can do whatever the f–k they want as long as they pay me.”

Ellroy is currently writing a “Second L.A. Quartet” taking place during the Second World War, with some characters from the first L.A. Quartet and the Underworld USA Trilogy returning younger. The first book, Perfidia, was released on September 9, 2014. The second book is titled This Storm which has a release date of May 14, 2019. It was released May 30, 2019, in the United Kingdom, and June 4, 2019 in the United States.

Ellroy in collaboration with the Los Angeles Police Museum and Glynn Martin, the museum’s executive director, released LAPD ’53 on May 19, 2015. Photography from the museum’s archives are presented alongside Ellroy’s writings about crime and law enforcement during that era.

On April 29, 2015, Ellroy and Lois Duncan were the Grandmasters at the 2015 Edgar Awards.

In the fall of 2017, Ellroy investigated the murder of Sal Mineo. Reminiscent of how he investigated his mother’s unsolved murder, Ellroy worked with Glynn Martin, an ex-LAPD officer, the LAPD Museum’s current executive director, and co-author of LAPD ’53. Ellroy wrote about this investigation for The Hollywood Reporter in digital form on December 21, 2018, and it also appeared in published form in the December 18th, 2018 issue of The Hollywood Reporter magazine.

Early in January 2019, Ellroy- possibly typing it himself- posted news on the website jamesellroy.net, quote “I’m digitally illiterate, so you’ve got to gas on the fact that I’m breaking baaaaaaaaad from tradition, in order to post this announcement.” Ellroy posted that he had been inducted into the Everyman’s Library series. Three Everyman’s Library editions will be reprinted: The L.A. Quartet, The Underworld U.S.A. Trilogy, Volume I and The Underworld U.S.A. Trilogy, Volume II. The release dates for these editions, as well as This Storm: A Novel, is June 4, 2019. James Ellroy stated “Stay stirringly tuned to this website for further updates.” and simply signed the finished post, Ellroy with a dog’s pawprint below it.