Doug Ross

In the pilot episode, which takes place on St. Patrick's Day 1994, Ross is brought into the ER not long before his shift, to be "treated" for drunkenness by his longtime friend, Dr. Mark Greene. Viewers also see Doug's reaction to the near-death of his ex-girlfriend, nurse Carol Hathaway, after she is brought into the ER as a patient following a suicide attempt.

Throughout the next few seasons, Ross is shown to be compassionate, though not always using the best judgment. His love of children is best seen during darker situations, such as when a child is in danger. When Peter Benton talks about how surgeons deal with emotionally charged cases and ER doctors have it easy, Ross leaves him speechless by describing cases that include a young girl who beat her mother to death, a kid who is going to lose his leg to cancer and another kid who is dying from a life of homelessness. His brashness leads him to confront parents he thinks are irresponsible, and in one instance he publicly assaults a man who had abused his daughter; Ross's counseling in that case just consists of a shrink telling him not to do that again.

He is a passionate doctor who puts the welfare of his patients, especially children, above his medical career. In the Season 2 episode "Hell and High Water," Dr. Ross saves a young boy who nearly drowns in a flooded storm drain and commandeers a news helicopter to take him to County General, with much of his attempts to save the child being shown on live TV. This garners him much attention, earns him an award, and saves his job. Ross doesn't handle authority well, even when Mark is his boss. Despite being a pediatrician, in several episodes he's asked to perform medical procedures on adults, usually when the other doctors are busy.

In another episode, he tries to do an ultra-rapid detox on a drug-addicted baby without the mother's consent. Hathaway assists, but when Greene and Dr. Kerry Weaver discover that the procedure is being done in violation of hospital policy and the law, Doug is punished. He is left on probation for 30 days and is supervised by Drs. Weaver and Greene, who have to co-sign his charts. Doug's attitude toward patient treatment often has consequences for his coworkers and supervisors, who have received reprimands from their superiors for his actions.

In Season 4 he vies to be an attending physician for emergency pediatrics. He eventually gets the job, even though Greene and Weaver oppose his promotion because the position isn't necessary and the funds are needed elsewhere. Greene is ultimately happy for Ross, but Weaver is aghast and campaigns against his new position.

He resigns in Season 5 following a scandal in which he shows a mother how to bypass the lockouts on a Dilaudid PCA, enabling her to give a lethal dose of medication to her terminally ill son. Ross had earlier stolen Dilaudid from a pain-medication study and given it to the mother, only to be discovered by Weaver and Greene, who reprimand him but kept the incident private. The incident prompts the closure of Hathaway's free clinic in the hospital, since it supplied the PCA to this mother, and Ross faces suspension from work and possible criminal charges.

A friend of Ross, who is the Chief of Genetics, stands up for him and the charges against him are dropped, but Ross resigns from the hospital and moves to Seattle. When Ross leaves, he and Hathaway are on poor terms until she discovers that she's pregnant with his twin girls. Her clinic is later re-opened, but she has to report to her former assistant there.

Ross was written out of the series because Clooney wished to focus on his expanding film career. He also said that there wasn't any strong story in place for his character after Season 5. He appeared at the end of the penultimate episode of season 6, when Carol leaves Cook County to reunite with Ross in Seattle. He was reportedly asked to return briefly in season 8, to make an appearance in Anthony Edwards's last episode during Greene's funeral, but Clooney declined because he did not want his cameo appearance to overshadow the departure of a beloved character on the show.

Clooney returned to ER for its 15th and final season in 2009 in a story arc beginning with Episode 328, titled "Old Times", with Julianna Margulies also returning as Hathaway. In the episode, the two are now married and work to help convince a grieving grandmother to donate her grandson's organs. During the process, Doug talks with Neela Rasgotra and learns that nearly everyone he knows has since departed County with Anspaugh being the only one left. At the end of the episode they receive word of the success of their efforts, unaware that the doctor who got the kidney was their old friend John Carter.

George Clooney did not receive a casting call for the television series. He received a draft of the script from a friend; he read it and became interested in the part. He said: "I like the flaws in this guy. I can play him."[4]

The character was described as "a complicated children's doctor who could be self-centered, quick-tempered, and giving, hitting the bottle to avoid dealing with consequences of his actions."[5]

ER executive producer John Wells originally intended for Doug Ross' relationship with an unknown son to be a bigger part of his character, saying in 2019, "There are people among us who lose track of their children. [George and I] talked about it at the time. We both know people, know men, who had children that they have no contact with for whatever reason. That's what we were trying to play with." However, Doug's son is only mentioned in one episode of ER.[6]

Until he restarts and strengthens his relationship with head nurse Carol Hathaway, Doug is shown to be a womanizing character who is involved with many women.