John Patrick "Jack" Ryan, Sr., KCVO, (Hon) is a fictional character by Tom Clancy who appears in many of his novels and their respective film adaptations. The character is born in Baltimore in 1950 and grows up there. He earns an NROTC commission in the Marines at Boston College. Medically retired following a helicopter crash, he works as an investment broker. He meets and marries Caroline "Cathy" Mueller, a medical student and later an ophthalmic surgeon, with whom he has four children.