Caroline "Cathy" Ryan (née Muller) is the wife of Jack Ryan, Sr., Mother of Sally, Jack Jr, Katie, and Kyle and daughter of Joe Muller. Cathy is also the aunt of Brian Caurso and his twin brother Dominic Caurso. Cathy was a ophthalmic surgeon at the Wilmer Eye Institute of Johns Hopkins University School of Medicine and a Professor of Surgery at Johns Hopkins. She later became the first lady when her husband became the President of the United States.
- In the first film her name is Caroline, but in the last three films her name is Catherine.
Five movies have been produced based on Tom Clancy novels featuring Jack Ryan, starring four different actors as Cathy Ryan: