Colin Armstrong (b. 1961), usually known by the pen-name Chris Ryan, is a British author, television presenter, security consultant and former Special Air Service sergeant.
After the publication of fellow patrol member Andy McNab's Bravo Two Zero in 1993, Ryan published his own account of his experiences during the Bravo Two Zero mission in 1995, entitled The One That Got Away. Since retiring from the British Army Ryan has published several fiction and non-fiction books, including Strike Back, which was subsequently adapted into a television series for Sky 1, and co-created the ITV action series Ultimate Force. He has also presented or appeared in numerous television documentaries connected to the military or law enforcement.