Christa Miller

Jordan Sullivan, played by Christa Miller, is Dr. Cox's acerbic ex-wife and current partner, and a hospital employee. Through most of the show, she was a member of the hospital’s board of directors, and so would only appear at the hospital on occasion, and would act quite hostile towards most of the hospital’s employees. As such, much of her role on the show was originally focused on her and Cox’s private relationship (although this has changed in recent years since Jordan became a full-time employee at the hospital).

Although not much is known about Jordan's personal background, a few details of her life have been revealed throughout the course of the show. Dr. Cox implies on one occasion that Jordan is five years younger than him, which would probably place her birth somewhere around 1967. She has a sister named Danni (played by Tara Reid), who dated J.D., and a (now deceased) brother named Ben (played by Brendan Fraser) who was Dr. Cox's best friend. Her father, Quinn, occupied a position in the hospital board of directors, a position which Jordan inherited after his death. She had an abortion when she was 19 after being impregnated by her then-boyfriend's best friend, who she says was the first man she'd ever been with (in another episode, however, she claims to have given up a baby while she was in high school).

It appears that she and Dr. Cox have known each other for a very long time, at least since Dr. Cox was an intern (approximately 20 years ago). Although it isn't clear when their relationship started, it is known that they were already a couple by the time Cox occupied the position of Chief Resident at the hospital. They would eventually marry, only to get divorced five years later (shortly before the show's first season) due to Jordan's infidelity (specifically, she cheated on Cox with his then-protégé and former co-worker, Dr. Pete Fisher). Their separation would last approximately 18 months, during which Cox and Jordan maintained a meaningless, strictly sexual relationship.

They officially became a couple again during the show's second season, after Jordan showed up unexpectedly carrying Dr. Cox's child, Jack. Although he was initially unaware that he was the father (Jordan had lied by saying it was the child of a "Greek bellboy" because she didn't want Cox to feel pressured into being with her), he would eventually find out at the end of the second season, some time after Jack had been born. Since then, Cox and Jordan have rebuilt their relationship and now live together (though they have chosen not to get married), and she has shown herself to be a good mother. Though she and Cox constantly bicker, it is occasionally implied that this is merely their own twisted way of showing affection to each other, and on one occasion, was comically presented as an analogy for the sexual component in their relationship ("My Self-Examination"). Even though Jordan constantly berates and insults Cox, she has also been shown to be a loving partner who craves his respect and approval ("My Changing Ways"), and cares for him very deeply "My Lucky Charm". In "My Transition", it was revealed that she is pregnant with their second child.

Jordan is possibly the only person to top Dr. Cox in vindictiveness, coldness, and overall unpleasantness. She is certainly his only rival for sheer sarcasm, and is seemingly the only person able to effectively retort to Cox's many remarks and rants. She has stated on several occasions that she "feel[s] dead inside" and seems to feel minimal emotions, if any. Despite her attitude, however, she has been shown to be incredibly loyal to those she feels close to (whether this is out of friendship or sheer possessiveness is a different question, however), and on one occasion even helped series protagonist J.D. break up with his domineering girlfriend ("My Female Trouble"). In recent years, and despite her vindictiveness, she has attempted to soften her personality after obtaining a full-time position at the hospital and becoming pregnant for a second time, and has since become friendly with Carla and Elliot.

Jordan is now the mother of two children, Jack and Jennifer. She allowed J.D. to be Jennifer's godfather and to choose her name because he was the only one who came to visit her in the hospital.