John Marcum Wells is an American producer, writer, and director. He is best known for his role as showrunner and executive producer of the television series ER, Third Watch, The West Wing, Southland, Shameless, Animal Kingdom, and American Woman, as well as the miniseries Maid and the upcoming series Rescue: HI-Surf. His company, John Wells Productions, is currently based at Warner Bros. studios in Burbank, California. Wells is also a labor leader, having served as president of the Writers Guild of America, West from 1999 to 2001 and from 2009 to 2011. Wells serves on the Motion Picture & Television Fund (MPTF) Board of Governors. In 2011, he developed the series Shameless on Showtime, which ran for eleven seasons ending in 2021.

ER is an American medical drama television series created by Michael Crichton that aired on NBC from September 19, 1994, to April 2, 2009, with a total of 331 episodes spanning 15 seasons. It was produced by Constant c Productions and Amblin Television, in association with Warner Bros. Television. ER follows the inner life of the emergency room (ER) of Cook County General Hospital in Chicago, and various critical issues faced by the department's physicians and staff.