Leonard, whose ear for gritty, realistic dialogue helped bring dozens of hard-bitten crooks, cops and cowboys to life in nearly 50 novels, died on Tuesday at age 87, according to his website, weeks after a stroke.
"Elmore passed away this morning at 7:15am at home surrounded by his loving family," the announcement on elmoreleonard.com said, adding that more details would follow.
Leonard, who first wrote westerns when he gave up his advertising agency job in the 1950s before moving on to crime and suspense books, suffered a stroke on July 29.
Known by the nickname Dutch, Leonard had his commercial breakthrough in 1985 with the publication of Glitz.
His following books, including Get Shorty, Out of Sight, Killshot, Bandits and Freaky Deaky, came out every year-and-a-half or so and were best-sellers.
Hollywood had an affinity for Leonard's books, and more than 25 of his works were made into movies or television shows, beginning with Paul Newman in the 1967 film Hombre.
The western story 3:10 to Yuma and the novel The Big Bounce were each adapted for film twice.
The cable television series Justified, the tale of a US marshal in Kentucky that first aired in 2010, was based on Leonard's work and he served as executive producer of the show.
Movie producers and stars were so anxious to secure rights to his books that they were known to show up on Leonard's doorstep on the publication date. Leonard's 47th book, Blue Dreams, was expected to be published this year.
"I don't have any reason to quit," Leonard told Reuters in 2012, referring to his career. "I still enjoy writing."
Leonard won the National Book Foundation's Medal for Distinguished Contribution to American Letters in November 2012, putting him in the company of such US literary luminaries as Toni Morrison, John Updike, Gore Vidal and Norman Mailer.
He was married three times and had five children with his first wife. His son Peter also went into advertising before becoming a writer. – Reuters