Flames broke out around 10:30 p.m. inside the first floor of the building on Ocean Parkway near Foster Avenue in the Midwood area.
Firefighters tried to tackle the fire as fast as they could, but when it was finally out, they found 11-year-old Shirr Teved unconscious and unresponsive.
She was rushed to Maimonides Medical Center, where she was pronounced dead.
A firefighter was also seriously hurt and had to be pulled from the home, but he is expected to recover.
Meanwhile, the cause of the deadly blaze is under investigation.