The blaze broke out at 2:30 a.m. at a 3-story row house in the 3300 block of Gratz Street.
It took about half an hour for firefighters to get the upper hand.
Medics took one person to Temple University Hospital with injuries not believed to be life-threatening.
The Red Cross was working to find temporary shelter for the eleven people put out of their homes.
The cause of the fire is under investigation.