Toronto police responded to a call at 2:30 Sunday morning at the Empire nightclub on Cumberland Street and found people running from the area.
Some people were located at the scene with non-life-threatening gunshot wounds, while others attended hospital on their own, police said.
Five people were injured in the shooting and were treated in hospital.
Police allege that a man was located near the shooting scene with a loaded gun.
A 26-year-old man has been charged with a number of firearm offences, according to police.
Police continue to investigate and review security footage.
Anyone who may have been injured in the shooting is encouraged by police to seek medical attention.
Police are asking that anyone with information to call them or Crime Stoppers.