is a fictional character on the American comedy-drama Scrubs, played by Zach Braff. For his portrayal of the character, Braff was nominated for a 2005 Emmy Award and received three consecutive Golden Globe nominations in 2004, 2005 and 2006. J.D. is the narrator and main character of the series. He provides voice-over to the series which fills the roles of his internal thoughts and an overall narration in the show, often linking the story arcs in each episode thematically. J.D. has appeared in every episode during the first eight seasons except two season 8 episodes, "My Absence," in which he is only heard through a cellphone, and "My Full Moon". Braff was a regular cast member for the first eight seasons, and appeared in six episodes of season nine to help transition the series into its new format.

Dr. Cox is sarcastic and misanthropic, with a quick, cruel wit who claims that the most amusing thing about himself is that he 'commits' to his jokes. He is athletic, often found playing basketball in the hospital's parking lot with younger hospital employees. Dr. Cox has mentored several residents. Some mentioned in the show include Dr. Fisher, JD and in season 9, Drew. In the end of Season 8, Dr. Cox mentions that JD was a "darn good exceptional physician" and as good as him.

Neil Flynn originally appeared as a recurring guest star throughout Season 1, although appearing in all 24 episodes of that season. He was promoted to a series regular beginning with Season 2. He was a regular cast member until Season 8. He made his final appearance in the Season 9 premiere, "Our First Day of School". Janitor appeared in every episode during the first eight seasons except Season 2's "My Lucky Day" and Season 8's "My Last Words", "My Absence" and "My Full Moon". He has, throughout every season of the show, made it his goal to physically and mentally abuse J.D.

Christopher Turk, commonly known by his surname, is the best friend and former roommate of the series' protagonist, J.D (Zach Braff). He is currently the chief of surgery at Sacred Heart Hospital, where the series takes place, and is married to Carla Espinosa (Judy Reyes), the Head Nurse. He and Carla have a toddler daughter, Isabella ("Izzy"), as well as another daughter mentioned in season 9.

Bob Kelso is the chief of medicine for Sacred Heart Hospital for the first seven seasons of Scrubs, though he resigns in the episode "My Dumb Luck". He is portrayed as a cruel, heartless man who consistently prizes the hospital's bottom line and his own personal comfort over the patients' well-being. However, his callous demeanour hides a softer, compassionate side.

Theodore "Ted" Buckland, played by Sam Lloyd, is Sacred Heart's lawyer and, unlike other employees, feels that both the Democratic and Republican parties have good points. Ted is the hospital's "sad sack," and has little self-esteem. He is constantly degraded by Kelso, and it has been shown that, before working with him, Ted was not bald. But he has said in a previous episode to the Janitor that he started losing his hair in the eighth grade. It is implied that Ted has never won a case and it took him five tries to pass the Bar Exam due to stress induced Dyslexia; he also states that he took the exam in Alaska where it is much easier to pass.

The Todd is a surgeon who works at New Sacred Heart. Despite his jock-like disposition, he is known to be a talented and knowledgeable surgeon. The Todd's greatest joy in life is sex. Although he hasn't slept with nearly the amount of women he brags about, he makes sex jokes and innuendos about sex or the ladies practically every time he speaks. He hits on all the ladies, over which Laverne and Carla get quite worked up. The Todd thinks that his womanizing problems come from his poor relationship with his mother.