The attack on members of the Royal Family at the beginning of the film was inspired by a similar true-life attempt to kidnap Princess Anne on March 20, 1974. She was in her car when a man shot her guard and driver. She was subsequently helped by a passerby who attacked the criminal and saved her.
Author Tom Clancy disassociated himself from the production after reading the first draft of the script.
During the shooting of the climactic fight scene between Ryan and Miller on the boat, Harrison Ford accidentally injured Sean Bean by a blow with the boat hook, leaving a bleeding cut. The resulting scar was later used for Bean's title character in Sharpe (1993), enhanced by makeup.
Due to Harrison Ford's replacing Alec Baldwin, the age of Jack Ryan had to be changed from thirty-five to fifty.
The line "There's never been a terrorist attack on American soil" was included in trailers for the movie. However, it was left out of theatrical release because it sounded too much like an invitation or dare.