Chris ryan was born in Rowlands Gill, Tyne and Wear, North East England. After attending Hookergate secondary school, he enrolled in the Army as a boy soldier at 16. His cousin was in the 23rd SAS Reserves and invited Ryan to come up and "see what it's like to be in the army". Ryan did this nearly every weekend, almost passing selection several times, but he was too young to continue and do 'test week'. When he was old enough, he passed selection into the 23rd SAS. Shortly after that he began selection for the Regular 22 Regiment and joined 'B' squadron as a medic. Needing a parent regiment, Ryan and a soldier who had joined the SAS from the Royal Navy, spent eight weeks with the Parachute Regiment before returning to 'B' Squadron. He spent the next seven years carrying out both covert and overt operations with the SAS around the world.
Ryan's assignment included training Khmer Rouge troops in 1981 to attack Vietnamese forces that had pushed them out of Cambodia. Journalist John Pilger wrote in October 2009, "Incredibly, the Thatcher government had continued to support the defunct Pol Pot regime in the United Nations and even sent the SAS to train his exiled troops in camps in Thailand and Malaysia." In March 2009 Ryan admitted: "John Pilger, the foreign correspondent, discovered we were training the Khmer Rouge in the Far East. We were sent home and I had to return the £10,000 we'd been given to pay for food and accommodation.