Nelson Richard DeMille was born in New York City on August 23, 1943, to Huron and Antonia (Panzera) DeMille, and later moved with his parents to Long Island. He graduated from Elmont Memorial High School, where he was active in football and track. DeMille spent three years at Hofstra University before joining the Army. There, he attended Officer Candidate School and was commissioned a Lieutenant in the United States Army (1966-69), where he saw action in Vietnam as an infantry platoon leader with the First Cavalry Division. He was decorated with the Air Medal, Bronze Star, and the Vietnamese Cross of Gallantry, and was awarded the Combat Infantry Badge.

Following his discharge, DeMille returned to Hofstra University to receive his bachelor’s degree in Political Science and History. He is a father to three children: Lauren, Alexander, and James, and currently resides on Long Island.

DeMille's first major novel, By the Rivers of Babylon, was published in 1978, and like all his succeeding novels, is still in print. He has authored numerous action adventure and suspense novels, including Plum Island, The Charm School, and The Gold Coast. DeMille is a member of American Mensa, The Authors Guild, a past president of the Mystery Writers of America, and a Book-of-the-Month Club Judge. In 2015, he was chosen as ThrillerMaster of the Year by International Thriller Writers. He holds honorary doctorates from Hofstra University, Long Island University, and Dowling College, and is an Honorary Trustee of the Walt Whitman Birthplace Association.

Some of his notable works include Mayday (co-authored with Thomas Block), Cathedral, The Talbot Odyssey, Word of Honor, The General's Daughter, Spencerville, The Lion's Game, Up Country, Night Fall, Wild Fire, The Gate House, The Lion, The Panther, The Quest, Radiant Angel, The Cuban Affair, The Deserter (co-authored with his son, Alex DeMille), The Maze, and Blood Lines (co-authored with Alex DeMille). Nelson DeMille has also contributed short stories to anthologies, and book reviews and articles to magazines and newspapers.