Nurse Carol Hathaway is a fictional character from the television series ER, which aired from 1994 to 2009. Portrayed by actress Julianna Margulies, she is known for her strong, compassionate demeanor and her dedication to patient care. Carol starts as a nurse in the emergency room of Chicago's County General Hospital and becomes a central figure throughout the series. Throughout her time on ER, Carol faces various personal and professional challenges, including her relationships with colleagues like Dr. Doug Ross, played by George Clooney. Her character evolves significantly, showcasing her resilience and commitment to the nursing profession while navigating the complexities of hospital life.