Nelson Richard DeMille was born in New York City on August 23, 1943, to Huron and Antonia (Panzera) DeMille. He moved with his parents to Long Island, where he graduated from Elmont Memorial High School. DeMille played football and ran track during his high school years.

He spent three years at Hofstra University before joining the Army, where he attended Officer Candidate School and was commissioned as a Lieutenant in the United States Army (1966-69). Nelson DeMille served in Vietnam as an infantry platoon leader with the First Cavalry Division. He was decorated with the Air Medal, Bronze Star, the Vietnamese Cross of Gallantry, and received the Combat Infantry Badge.

After his military service, DeMille returned to Hofstra University and earned a bachelor’s degree in Political Science and History. He has three children: Lauren, Alexander, and James, and resides on Long Island.

DeMille's writing career took off with his first major novel, By the Rivers of Babylon, published in 1978. This book remains in print, along with all his subsequent novels. His famous works include Plum Island, The Charm School, and The General's Daughter. He has also written under the pen names Jack Cannon, Kurt Ladner, Ellen Kay, and Brad Matthews.

Nelson DeMille is a member of American Mensa, The Authors Guild, and has served as past president of the Mystery Writers of America. He was a Book-of-the-Month Club Judge and is also affiliated with International Thriller Writers, where he was named ThrillerMaster of the Year in 2015. Additionally, he is an Honorary Trustee of the Walt Whitman Birthplace Association and holds three honorary doctorates from Hofstra University, Long Island University, and Dowling College.