Live action TV
Description
The name Catherine appears in the Golgo 13 franchise in two distinct capacities, each belonging to a different adaptation. One is a character from the 1973 live-action film, and the other is a client from episode 26 of the 2008 television anime series.

In the 2008 anime television series, a character named Catherine appears in the episode titled Cold-Blooded Catherine. Her background is that of a former terrorist who was once infamous for her cold-hearted actions. In that past life, she had hired the assassin Golgo 13 for her own purposes. However, following the death of her son, she undergoes a profound transformation and abandons her violent past to embrace pacifist ideals. Her motivation in the episode is born from this new philosophy. When a younger, radical friend named Pamela kills a mutual acquaintance, Catherine decides to act in order to prevent further bloodshed. Her role in the story is that of a client and a decoy. She approaches Golgo 13 to eliminate Pamela, acknowledging that she has no means to pay for his services, which he accepts regardless. Catherine devises a plan to lure the paranoid Pamela to a specific spot and give Golgo a signal to shoot through a blackout curtain. The climax of the episode reveals the tragic nature of her development and her key relationship with Golgo. During the meeting, an argument erupts, and Pamela shoots Catherine. Even after being shot, Catherine fulfills her role, and the remaining bullet hole in the window from her own wound allows Golgo to calculate Pamela's position and complete the assassination. Her notable ability is not physical combat, but the strategic thinking required to set up the blind sniping scenario, as well as her personal resolve to sacrifice herself for her pacifist goals.

In the 1973 live-action film, a different character named Catherine Morton appears as a primary supporting role. Her background is that of a female secret police agent who works for the organization that has hired Golgo 13 to assassinate a crime boss. She is sent to Tehran to work with him, officially under the guise of being his wife, though she is also a field operative tasked with observing him. Her personality is presented as assertive and immediately attracted to the stoic assassin. While expressing disgust at the idea of working with a cold-blooded killer, she quickly falls for his rugged masculinity and insists on playing her part as his wife to its fullest extent. Her motivations shift from being a professional operative to a woman seeking a romantic connection, seeing Golgo as a romantic interest despite his detachment. Her role in the film is that of a love interest and a burden. She follows Golgo to Tehran, sleeps with him, and then pursues him when he attempts to leave her behind. This leads to her becoming a liability. In the climax, she is captured by the villains and used as a hostage. Her key relationship is with Golgo, for whom she declares her love just before being killed by the antagonist. Her development is minimal, serving primarily to highlight the protagonist's lone-wolf nature and the dangerous world he inhabits. She notably criticizes his worldview by stating that for him, women are just lubricating oil for a killing machine. Her abilities are not combat-oriented; her function is administrative and intelligence-based, though the film primarily showcases her role as a romantic pursuer rather than an operative.