Lee Earle "James" Ellroy (born March 4, 1948) is an American crime fiction writer and essayist. Ellroy has become known for a telegrammatic prose style in his most recent work, wherein he frequently omits connecting words and uses only short, staccato sentences, and in particular for the novels The Black Dahlia (1987) and L.A. Confidential (1990).

Lee Earle "James" Ellroy was born in Los Angeles. His mother, Geneva Odelia (née Hilliker), was a nurse. His father, Armand, was an accountant and a onetime business manager of Rita Hayworth. His parents divorced in 1954, after which Ellroy and his mother moved to El Monte, California.

At the age of seven, Ellroy saw his mother naked and began to sexually fantasize about her. He struggled in youth with this obsession, as he held a psycho-sexual relationship with her, and tried to catch glimpses of her nude. Ellroy stated that "I lived for naked glimpses. I hated her and lusted for her..."

On June 22, 1958, when Ellroy was 10 years old, his mother was raped and murdered. 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. His father was more permissive and allowed Ellroy to do as he pleased, namely be "left alone to read, to go out and peep through windows, prowl around and sniff the air." The police never found his mother's killer, and the case still 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), were important events of Ellroy's youth.

Ellroy's inability to come to terms with the emotions surrounding his mother's murder led him to transfer them onto another murder victim, Elizabeth Short. Nicknamed the "Black Dahlia," Short was a young woman murdered in 1947, her body cut in half and discarded in Los Angeles, in a notorious and unsolved crime. Throughout his youth, Ellroy used Short as a surrogate for his conflicting emotions and desires. His confusion and trauma led to a period of intense clinical depression, from which he recovered only gradually.

In 1962, Ellroy began to attend Fairfax High School, a predominantly Jewish high school. While in high school, he began to engage in a variety of outrageous acts, many anti-Semitic in nature. He joined the American Nazi Party, purchased Nazi paraphernalia, sang the Horst-Wessel-Lied at school, mailed Nazi pamphlets to girls he liked, openly criticized John F. Kennedy, and ironically advocated for the reinstatement of slavery. His "Crazy Man Act", as Ellroy describes it, was a plea for attention and got him beaten up and eventually expelled from Fairfax High School in 11th grade, after ranting about Nazism in his English class.

Ellroy's father died soon after this, with his father's last words to him being, "Try to pick up every waitress who serves you."

After being expelled from high school, Ellroy then joined the U.S. Army for a short period of time. On enlisting, Ellroy soon decided he did not belong there and convinced an army psychiatrist he was unfit for combat. He was discharged after three months.