MacDonald died in the fire at his home at 190 Hilltop Crescent, according to Contra Costa County Sheriff's Office spokesman Jimmy Lee.
Fire crews and sheriff's deputies were called to reports of a fire at the home around 9:38 p.m., Lee said.
The first deputy who arrived on scene attempted to locate any residents inside but was unsuccessful due to extensive flames and smoke, according to the spokesman.
Firefighters found MacDonald inside the home after extinguishing the blaze. He was pronounced dead at the scene.
The sheriff's office and the Contra Costa County Fire Protection District are jointly investigating the death.
An autopsy will be performed on Monday, Lee said.