Every Actor On The Pitt Who Also Appeared On ER

Noah Wyle isn't the only actor with ties to both Cook County General and Pittsburgh Trauma Medical Center.

Though HBO Max's "The Pitt" is in no way, shape, or form a continuation of "ER," the two medical dramas share more than just Wyle. Several key creatives overlap — including series creator R. Scott Gemmill, executive producer John Wells, and physician-writer Joe Sachs — along with a growing list of familiar faces in front of the camera.

So, TVLine is tracking every performer who has appeared on both doctor dramas — a list we'll routinely update as "The Pitt" continues its acclaimed run, now extended through Season 3.

In addition to naming each actor, we've also noted which "ER" episodes they appeared in, should you decide to take a stroll down memory lane as you await the next new episode of "The Pitt."

Long before she became Pittsburgh Trauma Medical Center charge nurse Dana Evans on "The Pitt," Katherine LaNasa guest-starred on Noah Wyle's previous medical drama, "ER." Despite their shared TV lineage, LaNasa has no memory of crossing paths with Wyle during her brief stay at County.

"I don't even think I met Noah [at the time]," LaNasa told TVLine. She did recall meeting Maura Tierney, thanks to a mutual connection: Tierney had starred on "NewsRadio" with Vicki Lewis, while LaNasa appeared alongside Lewis on another NBC sitcom, "Three Sisters."

LaNasa appeared in Season 9, Episode 4 as Janet Wilco, an overly flirtatious mom who winds up in a storage closet with Goran Višnjić's Dr. Luka Kovač. When auditioning for the role, she told TVLine she had watched "The English Patient" the night before.

"I was inspired by Kristin Scott Thomas to tap into that part of my sexuality required for that role, and I got it," she said. "I remember thinking, like, 'Yeah! The old girl got the part!'"

Before stepping into the role of Dr. Jack Abbot on "The Pitt," Shawn Hatosy made a lasting impression on "ER," guest-starring in Season 13, Episode 7 as Willis Peyton, a patient suffering from dissociative identity disorder. The episode was directed by John Wells, marking the beginning of a creative partnership that would span decades.

"That one role... changed everything," Hatosy told TVLine, explaining how the experience led to future collaborations with Wells, including starring roles on "Southland" and "Animal Kingdom," which ran for five and six seasons, respectively, on TNT.

"When you're doing a guest spot, you just don't know who you're going to change the mind of for the future," he said.

That partnership entered its third decade in 2024, when Wells enlisted Hatosy to recur on both "The Pitt" and Fox's short-lived "Rescue: HI-Surf." The former earned him his first Emmy for Outstanding Guest Actor in a Drama Series in 2025.

On "The Pitt," Michael Hyatt recurred throughout Season 1 as Pittsburgh Trauma Medical Center chief medical officer Gloria Underwood, a persistent thorn in Robby's side pushing for improved patient satisfaction scores in an already strained emergency department. Though Gloria is not seen in Season 2, she is referenced by new hire Dr. Baran Al-Hashimi (played by Sepideh Moafi).

Eighteen years earlier, Hyatt appeared in Season 13, Episode 12 of "ER" as Yvonne, a New Orleans expat who lost everything — including her husband — in Hurricane Katrina and ultimately has part of her leg amputated. It was a memorable one-off, particularly because Yvonne was the final patient treated by Laura Innes' Dr. Kerry Weaver before her resignation from County General. (Fun fact: Innes was the second longest-tenured "ER" cast member, behind only Noah Wyle, appearing in upward of 250 of the show's 331 episodes.)

On "The Pitt," Tracy Vilar recurs as Pittsburgh Trauma Medical Center ward clerk Lupe Perez, spending much of her screen time stationed behind a waiting room window.

Late in Season 1, however, as PTMC's frontline heroes responded to a mass-casualty event, Lupe was pulled into a far more harrowing role. Alongside social worker Kiara Alfaro (played by Krystel McNeil), she helped reunite anxious family members with shooting victims — or, in some devastating cases, assisted with identifying the dead.

Twenty-eight years earlier, Vilar appeared in two episodes of "ER" as Doris, a drug-addicted patient who first sought medical attention in one of the series' most memorable hours: the live Season 4 premiere, "Ambush." She returned three weeks later in Season 4, Episode 4, in which Doris unexpectedly went into labor and delivered a stillborn, blaming Nurse Carol Hathaway (played by Julianna Margulies) for her baby's death.

On "The Pitt," Ernest Harden Jr. recurred in Seasons 1 and 2 as frequent flyer Louie Cloverfield, appearing in 11 episodes. When he died of a massive pulmonary hemorrhage from end-stage liver failure in Season 2, Episode 6, we learned that, decades earlier, he lost his pregnant wife in a car accident — a trauma that shattered his life and sent him spiraling into alcoholism.

Twenty-four years before landing at PTMC, Harden Jr. guest-starred in Season 7, Episode 17 of "ER" — not as a patient, but as the unnamed son-in-law of a demented woman, Mrs. Howard, who got hold of a policeman's gun and was fatally shot by another officer.

On "The Pitt," Shu Lan Tuan recurred in Season 1 as Ginger Kitajima, an elderly patient whose daughter, Rita (played by Kayla Blake), brought her in after a fall into a rose bush. In need of around-the-clock care, Ginger's condition placed visible strain on Rita as a caregiver — yet Ginger remained upbeat, particularly when Dr. Robby indulged her request for a dance.

Twenty-one years earlier, Tuan appeared in Season 11, Episode 7 of "ER" as Mrs. Pak, the mother of Mi-Cha (played by Peggy Ahn), who arrived at County with stomach pain and unexpectedly gave birth to a healthy baby boy. After Carter broke confidentiality and told Mrs. Pak the truth, she voiced fears that her staunchly conservative husband would refuse to let their daughter return home. (The episode also featured a pre-fame Randall Park as Mi-Cha's developmentally delayed brother, Yong-Jo.)

On "The Pitt," Drew Powell recurred in Season 1 as patient Doug Driscoll, who arrived at PTMC with chest pain, only to spend hours sitting in chairs. He ultimately turned disruptive and combative, leaving AMA — but not before confronting charge nurse Dana and punching her in the ambulance bay.

Seventeen years before his time on the HBO Max medical drama, Powell appeared in Season 14, Episode 16 of "ER" as Dennis Voltaire, a father of 12 whose wife — pregnant with their 13th child — was rushed to County after a car accident. (Both mother and baby pulled through.)

On "The Pitt," Jenny O'Hara appeared in the Season 2 premiere as patient Candace O'Grady. Under the care of Dr. Samira Mohan (played by Supriya Ganesh), Candace confided that she stopped taking her prescribed medication after discovering what she believed to be an alternative treatment. She explained that she and a friend experimented with marijuana, and that she had since taken to consuming large quantities of pot-laced cookies, resulting in intractable vomiting.

Thirty years earlier, O'Hara appeared in back-to-back episodes of "ER" as floor nurse Rhonda Sterling. First pulled down from the ICU in Season 3, Episode 6 to assist Carol Hathaway (played by Julianna Margulies), Rhonda struggled with the pace of County's emergency department and accidentally handed Carol the wrong injectable during a trauma. After a second critical error in the following episode led Carol to write her up, Rhonda revealed she was just nine months away from her pension — and that someone higher up was deliberately floating her into unfamiliar departments in an attempt to get her fired. Rather than endure further humiliation, she decided to quit, forfeiting her pension altogether.

On "The Pitt," Rusty Schwimmer recurs as retired hospital clerk Monica Peters, who returns to PTMC as a favor to Dana after the hospital goes analog to fend off a cyberattack.

Thirty-one years before her time at the admin desk, she guest-starred opposite Noah Wyle in Season 1, Episode 22 of "ER" as Ms. Grollman, a homeroom teacher who rushes her diabetic student to County.

On "The Pitt," Jeff Kober recurs in Season 2 as Duke Ekins, a motorcycle engineer who helped Robby bring his 1969 Bonneville back to life after rescuing it from a junkyard. After he's admitted as a patient, tests reveal that the lifelong smoker has an unidentified but potentially serious swelling in his chest cavity that requires further evaluation.

Twenty-four years before portraying a reluctant patient, Kober guest-starred in Season 9, Episode 8 of "ER" as a husband and father of two whose wife and sons are struck by a drunk driver. After his wife dies, he faces a nearly impossible choice: To save one son, he must agree to take the other off life support so his organs can be donated to his brother.

TVLine exclusively reported that Mary McCormack has been cast in "The Pitt" Season 2 as PTMC neurosurgeon Dr. Linda Conley, who makes her debut in Episode 13.

The role reunites McCormack with Wyle 20 years after her recurring turn on "ER," where she appeared in six episodes (Season 10, Episodes 2 and 10, and Season 12, Episodes 14, 15, 19, and 20) as Darfur clinic physician Debbie.

Of course, the face of both "ER" and "The Pitt" is Noah Wyle, who earned five consecutive Emmy nominations for Outstanding Supporting Actor in a Drama Series for his role as Dr. John Truman Carter III — and, 26 years after his last nomination, secured his first win in 2025 for Outstanding Lead Actor in a Drama Series for his turn as Dr. Michael "Robby" Robinavitch.

In the first of several interviews with TVLine tied to "The Pitt" Season 1, Wyle reflected on how the project evolved as its creative focus sharpened. 

"The idea was to take a look at what was happening to the people that were on the front lines... and seeing how there appeared to be two different health care systems in our country — those for people who have money and insurance, and those who don't," he said. "The more we went down that road, the more the point got obscured in the reunion aspect, the retread aspect, the reboot aspect... so I was not sorry when we were forced to pivot [away from 'ER'] and figure out how to tell the story in a new way."

That pivot — along with making the series for streaming rather than network television — ultimately expanded its creative possibilities. "Because you're no longer [bound by] standards and practices and language barriers, you really can paint with all the colors on the palette," Wyle explained.