Three specialist water rescue teams from West Yorkshire Fire and Rescue Service were called to the scene at Riverside Court in the Call Lane area of the city centre after emergency services were alerted to the incident shortly before 6am.
Firefighters from Leeds, Hunslet and Rothwell helped to rescue the man who was found to be suffering from shock and hypothermia.
After being removed from the cold water, the man was taken into the care of paramedics who then transported him to hospital in an ambulance.
Despite repeated safety warnings from police, Saturday’s rescue is another incident that has required an emergency response in recent months.
In February, police searched the Aire after reports of someone entering the river and not resurfacing, while underwater teams searched the river for a missing man who fell into the river on Boxing Day.