The incident happened around 3:05 p.m. near the 2500 block North Lake Shore Drive in Lincoln Park.
A first responder boat was seen bringing the person who was rescued to Diversey Harbor, where they were taken away by an ambulance. Fire officials said the person was taken to a hospital in critical condition.
Chicago police later said the person, a 32-year-old man, was pronounced dead at the hospital.
He was later identified as 32-year-old Matthew McCullough of Chicago by the Cook County Medical Examiner's Office.
His cause of death was not yet known.
No further information was immediately available.