It happened at a house along the 500 block of Erickson Avenue in Hockessin, New Castle County.
Firefighters were called to the home at approximately 2:30 a.m.
Authorities say the victim was found dead inside the home. That person has not yet been identified.
Two firefighters were treated for minor injuries due to the blaze.
The state fire marshal's office is still investigating what sparked the fire.