The Porterville Fire Department responded to the old Porter Theatre on Mill Avenue and Second Street at 4:45 a.m. Sunday.
Firefighters say as crews put out the flames they learned someone was trapped inside.
43-year-old Anthony Drew was rescued from the building and taken to a hospital for smoke inhalation.
Investigators later determined he started the fire.
Drew has been charged with unlawfully causing a fire of a structure.
The flames caused significant damage to the theatre's roof.