Patrick K. O'Donnell has written ten critically acclaimed books that recount the epic stories of America's wars from the Revolution to Iraq. He is a premier expert on elite and special operations units and irregular warfare. O’Donnell’s books are described as “nonfiction that read like fiction.” O'Donnell is the leading expert on the Office of Strategic Service (OOS), the forerunner of the CIA and America's special operations forces in WWII. One of his books, We were One: Shoulder to Shoulder With the Marines Who Took Fallujah is required reading for Marines and is on the Commandant's Professional Reading List. During the Iraq war, he was embedded with military units as the only civilian combat historian to volunteer and spend three months in Iraq documenting the experiences of troops in battle.

On his second tour to Iraq, he served as a war correspondent for Men's Journal and FOX News, reporting on the conflict in Iraq from the perspective of the Marines on the ground. He is a frequent contributor to National Review, as well as a variety of nationally recognized publications.

O'Donnell provided historical consulting for DreamWorks' award-winning miniseries Band of Brothers and the Medal of Honor game franchise.