Leonard was born in New Orleans, Louisiana, the son of Flora Amelia (née Rive) and Elmore John Leonard, Sr. Because his father worked as a site locator for General Motors, the family moved frequently for several years. In 1934, the family settled in Detroit.  He graduated from the University of Detroit Jesuit High School in 1943 and immediately joined the Navy, where he served with the Seabees for three years in the South Pacific (gaining the nickname “Dutch”, after pitcher Dutch Leonard). Enrolling at the University of Detroit in 1946, he pursued writing more seriously, entering his work in short story contests and sending it off to magazines. He graduated in 1950 with a bachelor’s degree in English and philosophy. A year before he graduated, he got a job as a copy writer with Campbell-Ewald Advertising Agency, a position he kept for several years, writing on the side.

Leonard got his first break in the fiction market during the 1950s, regularly publishing pulp Western novels. Leonard had his first success in 1951 when Argosy published the short story “Trail of the Apaches”. During the 1950s and early 1960s, he continued writing Westerns, publishing more than 30 short stories. He wrote his first novel, The Bounty Hunters, in 1953 and followed this with four other novels. Five of his westerns were turned into major movies before 1972: The Tall T (Richard Boone), 3:10 to Yuma (Glenn Ford), and Hombre (Paul Newman), Valdez Is Coming (Burt Lancaster), and Joe Kidd (Clint Eastwood).

He went on to write seventeen novels and stories in the mystery, crime, and more topical genres which were made into movies between 1969 and 2013.  In 1985, his breakout novel, Glitz was published. At the time of his death he had sold tens of millions of copies of his novels.  Among his later movies are Jackie Brown (directed by Quentin Tarantino) which is a “homage to the author’s trademark rhythm and pace”; Get Shorty (1995, John Travolta and Gene Hackman); and Out of Sight (1999, George Clooney and Jennifer Lopez, directed by Steven Soderbergh).

He married Beverly Claire Cline in 1949, and they had five children together—three daughters and two sons—before divorcing in 1977. His second marriage in 1979, to Joan Leanne Lancaster (aka Joan Shepard), ended with her death in 1993. Later that same year, he married Christine Kent, and they divorced in 2012.  Leonard spent the last years of his life with his family in Oakland County, Michigan. He suffered a stroke on July 29, 2013. Initial reports stated that Leonard was recovering, but on August 20, 2013, Leonard died at his home in the Detroit suburb of Bloomfield Hills of stroke complications. He was 87 years old. Leonard is survived by his five children, 13 grandchildren, and five great-grandchildren.