Born in St. Paul, Minn., Flynn initially pursued a career in marketing after graduating from the University of St. Thomas in Minnesota. He left the industry to become an aviator with the U.S. Marine Corps in the early 1990s, but was medically disqualified because he was prone to seizures.
After being diagnosed with dyslexia, Flynn began reading and writing voraciously to cope with the condition and ended up self-publishing his first novel, Term Limits, in 1997. The book, which launched the terrorism-themed Mitch Rapp series, eventually landed Flynn a book deal and he went on to publish 14 novels, the most recent of which came out last year.
To date, Flynn has sold more than 15 million books in the United States alone, the AP reports. He was also a story consultant for Season 5 of 24. A film adaptation of his 2010 book American Assassin, starring Bruce Willis, is in the works.
In 2010, Flynn was diagnosed with stage three prostate cancer. He died at a hospital in St. Paul surrounded by family and friends, according to the AP. He is survived by his wife, Lysa Flynn, and their three children.