The Columbus fire department said the blaze was reported shortly before midnight Saturday in the house on the city's west side. When firefighters reached the scene, neighbors reported that people might be inside.
Battalion Chief Michael Fowler said firefighters entered the home and found three people in a room full of flames.
They were identified Sunday as 22-year-old Jerrica Francisco, her son Deshawn Francisco and 33-year-old Demetrius Chappell. Authorities were trying to determine if they lived in the house. Fowler did not know the man's relationship to the mother and child.
The cause of the blaze was unclear. Damage was estimated at $40,000.