The fire broke out in a second floor apartment on Glen Street just after 12:30 a.m. and quickly spread.
Dozens of residents were helped from smoke-filled apartments by responding firefighters.
Eleven residents were hospitalized, including a husband and wife who suffered burns.
The rest of the residents were overcome by the smoke.
"They woke up and smelled smoke, and the fire was in the kitchen," Glen Cove fire Chief Anthony Tripp said. "Husband and wife, they got a couple burns on their arms trying to put the fire out. The police arrived. They started evacuating the whole premesis. Three of my firemen happened to be down the block. They assisted police in getting everybody out."
In all, about 50 were evacuated from a dozen apartments.
Glen Cove's mayor opened City Hall to house the displaced residents, many of them Spanish speaking.
The cause of the fire is under investigation.