Cook County Hospital is a a public hospital in Chicago, providing all types of medical services for the residents. It was founded in 1832 and is known as an innovative teaching hospital, employing over 300 attending physicians and 400 fellows and residence, with 464 beds, and is part of the Illinois Medical District, which is one of the largest concentrations of medical facilities in the world.

The hospital was used as a teaching hospital by Rush Medical School until the Civil War, when it was transitioned to an army hospital. After the war, it continued its purpose as a centre for medical education and founded the first medical internship in the country in 1866.

By the 1900s, the hospital was overseen by surgeons and physicians in Chicago who volunteered their services at the hospital, and the building which was rebuilt in 1916 to be the modern facility it is today.

Cook County Hospital is regarded as one of the world's greatest teaching hospitals, many interns, residents, and graduate physicians came to see the medical and surgical advances. Innovations included the world's first blood bank and surgical fixation of fractures.